COVID-19 Vaccines: Types and Mechanisms of Action

Viruses use their spikes to attach themselves to human cells during an infection. It exploits the machinery of the host cell to replicate after entering the cell, creating viral proteins and genetic material. As the host cell dies, they are combined into new virus particles and discharged.

Resultantly, more cells are infected by new virus particles, which destroy body tissues and cause symptoms. Infected cells send out warning signals to the immune system by exhibiting viral protein fragments on their surfaces. By doing so, infected cells are believed to transmit the viral antigen to specific immune cells, such as cytotoxic T-cells, and so activate them. 

At the same time, detritus from dead cells and virus particles are taken up by so-called professional Antigen-Presenting Cells, the most effective of which are dendritic cells.

Dendritic cells patrol the tissues of the body, constantly sampling their surroundings for intruders. Dendritic cells swiftly leave the tissue after capturing the antigen and travel to the next lymph node, where they present the antigen to another type of immune cell known as helper T-cells. B-cells in lymph nodes are also activated by viral particles. 

These immune cell clusters collaborate to mount two types of antiviral immunity: 

1. Cell-mediated immunity 
2. Antibody-mediated immunity 

However, the procedure could take many weeks, during which time the person will be sick and the virus will have damaged a large number of cells.

Vaccines give viral antigens to the immune system without inducing disease. A vaccine-generated immune response is comparable to that induced by a natural infection, albeit some vaccinations may only induce antibody-mediated immunity, making them less effective. Even when there is no infection, the immune system can produce symptoms that resemble a mild infection. For a few days, the lymph nodes near the injection site may become swollen and sore as they begin to produce antibodies. This is proof that the vaccine is working against infection.

Many existing vaccinations contain a virus that has been attenuated or inactivated. Because the entire virus is used in these vaccines, significant safety testing is required. In those with weakened immune systems, attenuated vaccinations may still cause sickness. 

• Only antibody-mediated immunity is induced by inactivated vaccines (Sinovac, Covaxin). 
• Only a portion of the virus, usually a spike protein, is contained in subunit vaccinations (EpiVacCorona). 

Although these vaccinations do not cause disease, they may not be seen as a danger by the immune system and hence fail to elicit the desired immunological response.

As a result, adjuvants are frequently used to encourage antigen-presenting cells to recognize the vaccine. A subunit vaccination could alternatively be made out of empty viral shells that haven't been genetically modified. These vaccines may not require adjuvants to be seen as dangerous because they have the size and structure of a disease, but they are difficult to make.

Instead of the antigen itself, nucleic acid vaccinations contain genetic instructions for generating the viral antigen. Viral DNA is introduced into the nucleus of the cell, where it is translated into mRNA. In the cytoplasm, mRNA is translated into viral spike protein. Like other types of vaccines, the protein is then exhibited on the cell surface.

To reach the cell's nucleus, naked DNA vaccines (Inovio) require a specific delivery technique. Alternatively, a virus that isn't related to the DNA could be utilised to distribute it. The vaccine is also known as a viral-vector vaccine (Sputnik V; Johnson & Johnson's) in this situation. 

The Oxford-AstraZeneca Covid-19 vaccine, for example, uses a chimpanzee's adenovirus as a vector. The coronavirus spike gene is inserted to the adenoviral genome, which has been edited to eliminate viral genes. The viral vector cannot reproduce or cause disease in this manner, but it does serve as a vehicle for delivering the DNA. Because most people have been exposed to human adenovirus and have developed immunity to it, a non-human adenovirus is employed. Immunity may kill the vehicle before the DNA can be delivered, reducing the vaccine's effectiveness.

Concerns about viral DNA integration into the human genome have arisen as a result of DNA vaccinations. However, research in animal models have revealed that the incidence of integration is far lower than that of natural, spontaneous gene changes. 

mRNA vaccines (Pfizer, Moderna) deliver mRNA, which provides the instructions for producing the viral protein. mRNA molecules are transported in a lipid coating that will merge with the cell membrane when it reaches it. The mRNA is translated into viral antigen in the cytoplasm and subsequently presented on the cell surface. mRNA vaccines, unlike DNA vaccinations, are highly unlikely to incorporate into the human genome.  

Apart from all of the information we have so far, we are unable to compare any vaccine to another at this time. Because there is still a lot of research to be done on this subject.

Children's Mental Health and the COVID-19 Pandemic

Many of us reminisce back to our lives before the COVID-19 pandemic and hope for things to get back to the way that they were, while we simultaneously try to adapt to this new normal. The pandemic has affected our lives in numerous ways but it is imperative that we focus on our mental health. Many people have reported about the fear and uncertainty about their own health, the health of their loved ones, their financial situation and job outcomes as well as tackling social isolation through following public health protocols. 

Mental health is inclusive to all age groups and should leave no one behind in terms of spreading awareness. With this being said, 

Have you ever considered the effect that COVID-19 has had on children? 

We could say that children are unable to fully grasp the concept of their mental health and well-being, but the pandemic has taken away aspects of their life just like any other member of the community.

Read this blog post till end for some insight on the mental health of the children within our communities and how you as a parent guardian or any type of caretaker can help to ease their experience.

Although there are many factors to address, children are particularly vulnerable due to their limited understanding of the current pandemic. Because of this many of them are also unable to physically and mentally escape the harms of the situation as they have little to no coping strategies and it is hard for them to communicate their feelings easily unlike adults. 

Although their understanding is minimal, children can pick up on unverified information through social media or word of mouth as adults communicate which can aggravate mental distress and feelings of uncertainty as misinterpretation is bound to happen. 

Children are also in a continuous and critical period of development as they require special care in order to preserve and promote their mental health which has been primarily affected by a drastic change in routine. The suppression of all class activities and learning as well as a shift to an online schooling has led to the creation of an isolated learning environment. 

Essentially, schools are responsible for providing structure to a child's daily activities. Many articles have postulated the importance of physical activity during the quarantine as it is associated with a decline in symptoms of anxiety and depression. 

Research has also argued that schools play a primary role in providing a consistent daily calorie intake to ensure that children are getting their nutritional needs. These basic requirements have been drastically reduced because of pandemic.

A nationwide study in Canada conducted by the International Journal of Behavioral Nutrition and Physical Activity, found that children and youth were actually less active, played outside less, were more sedentary engaged in more recreational screen time and slept more in comparison to before the covid19 restrictions. But special needs are extremely vulnerable to the psychological impacts that come along, for example shifting to an online learning environment has disrupted their daily routines and therapy sessions. 

Children with autism or neurocognitive disabilities are more likely to show problematic behaviors such as irritability aggression and social withdrawal. 

Online learning has also led to a decrease in assistance to these children as parents cannot replace special education teachers. There is also a lack of technology to assist with this transition. In addition to that, social distancing and its effects are extremely new and difficult to understand especially for children that are experiencing developmental and intellectual delays. For these reasons spreading awareness of the mental health of children with disabilities needs to be done on a global scale.

It is also no surprise that the pandemic causes parents and caregivers to become fearful of their own concerns. Research shows that fear can be contagious as children are sensitive to the emotional state of the adults that surround them. 

To make matters worse, parents are also unable to alleviate the stress through familiar mechanisms that were established prior to the pandemic, such as visiting family and friends or going on excursions can actually decrease in frequency as there are limited ways for children to flee from perpetrators, as schools usually act as an avenue for children to report issues. 

Regardless, the frequency of children experiencing abuse at home may increase due to continuous contact with perpetrators in quarantine. Additionally, browsing on online social media platforms and lack of supervision over the internet access has also increased vulnerability to online offenders, attempted fraud and sexually inappropriate content. 

Due to these circumstances, issues such as deteriorating performance, aggression and regression may escalate. These are all examples of environmental impacts that impair a child's mental health and physical perception of the world around them. Despite any of the negative impacts the internet has been a critical tool for children and youth in learning, entertainment and even social interactions since the start of the COVID-19 pandemic. 

In particular research has shown that video games offer a temporary escape from real life, but they also provide a fair amount of social engagement. One of the greatest digital game distributors known as STEAM, reports that since the pandemic started the number of users has increased significantly. This report indicates that weekly users has increased from 19 million to 23.5 million. 

So what can you do to help your child during this pandemic.? 

Well, there are several avenues of support that can be offered for children to ensure that their mental health is being addressed. 

One of the main technique that is The CARD system provided by the hospital for sick kids for parents and caregivers. this system provides strategies that parents can play to help their children cope with stressful situations. 

CARD is an acronym that stands for Comfort, Ask, Relax and Distract.

The COMFORT aspect involves: 

• Talking to your child about what they can do to cope with their anxiety. 
• Try to empower your child to overcome their negative thoughts by saying things like "you are stronger than you feel". 
• Also be sure to validate your child's concern by saying things like "it's okay to be upset".
• Avoid focusing on the worry. 
• Limiting exposure to the media and news 
• Be mindful of the conversations that you have around family members
• Creating daily routines that give your child predictability and control. 

Next by ASKING questions your child is given an opportunity to open up. Some questions you can ask your child include: 

• What questions do you have? 
• How are you feeling? 
• What are your friends saying about this? 
• What fun things can you do today? 

Thirdly by RELAX this means: 

• To do things that you and your child enjoy to help them feel more secure and connected.
• Listening to a mindfulness or relaxation activity together. 
• Practicing positive self-talk.
• Engaging in an enjoyable physical activity. 

Lastly a great thing to do is DISTRACT: 

• Try to talk about things that are important to your child such as sports or exercising or art.
• Reading books. 
• Watching movies. 
• Playing board games. 
• Working on puzzles. 
• Helping your child with their homework. 

Using CARD you can make a personalized system for your child to make their routines during the pandemic a little less difficult and hopefully this benefits your mental health in return. Because mental health is inclusive to all.

VACCINE EFFICACY AND COVID MUTATION

Scientists were concerned early in the epidemic, fearing that the coronavirus may evolve into something more deadly. Unfortunately, that worry was verified in November 2020 when the first "variant of concern" was found. The newly identified variation, also known as COVID-19 - B117, has been linked to a large increase in cases particularly in London and south-east England and many other parts of the world. 

So, in this blog, I’ll be talking about COVID Mutations and what it means for us. So, Let’s begin by taking a brief look at mutations and how they occur.

In biology, a mutation is something that causes a change in the genetic material. Each and every element of a cell's existence is controlled by the same genetic material. A cell's genetic makeup determines how it develops, functions, behaves, responds, and finally dies. These mutations can occur for a variety of causes. It can occur as a result of errors, radiation damage, or chemical exposure.

In fact, mutations can happen at any time. As a result, mutations might be harmful, neutral, or even beneficial to an organism.

So, you might be wondering how Coronavirus is affected by mutation?

Well, the coronavirus attaches to our body's cells using a specific protein. Spike proteins are proteins that aid the COVID virus in latching onto human cells and initiating infection. Because of mutations in these proteins, the virus is able to adhere to our cells more firmly, making it more infectious. 

Furthermore, mutations in this area allow the virus to avoid our body's own immune system, allowing it to spread unchecked. This mutation has been termed as ‘E484K,' and as of December 1, 2021, the UK recorded a total of 14000 instances each day, with a decreasing trend. 

After this strain on 5th Jan 2021 – UK was reporting a record high 60000 cases per day with an increasing trend. It has been discovered that the new strain is more infectious than the previous ones. According to the CDC. "Multiple lines of evidence show that B.1.1.7 is more effectively spread than other SARS-CoV-2 variants". According to UK Biobank researchers, most patients infected with COVID-19 maintain the antibodies for three to six months.

Your antibodies may not be able to protect you if you come into touch with another strain of the virus, such as the extremely infectious variety from the United Kingdom, and physicians feel your risk of reinfection is considerable. This is concerning because it raises the risk of coronavirus reinfection, especially in severely or chronically sick individuals.

What does this mean for us in the present? 

Things appear to be on the mend for the time being. The need of fast and decisive action appears to have been recognised across the world. Countries shut off overseas travel as soon as the news of the new strain became public, particularly from the United Kingdom. Those who had already returned were tracked down, quarantined, and tested as soon as possible.  Even nations like India, where covid has already impacted over 10 million people, have successfully halted the spread of this alien strain.

What about the vaccine? 

Well, things are a little strange here. Studies were conducted in New York, Texas, and Cambridge to determine the efficacy of current vaccination alternatives against the new strain. They evaluated freshly vaccinated people' antibodies against the novel covid 19 UK strain. Their findings revealed that, while the vaccine's efficacy in protecting against versions harbouring the E484K mutation was somewhat decreased for some persons, it was still within acceptable limits for the majority of people. It's worth noting, however, that the research mentioned above are based on relatively tiny sample sizes, so any conclusions drawn aren't conclusive.

What does this mean for the future? 

This mutation is a foretaste of what's to come. Covid's future will be filled with fresh shocks and unknowns. The long-term effects of this epidemic are yet unknown. It's possible that another altered strain isn't far behind. On a more optimistic note, all hope is not gone; we have fresh information and experience with which to prepare.

We have global mass vaccination programmes that are coordinated by corporations all around the world and sponsored by governments, and they have the ability to permanently address this problem. To reduce the load, we're looking into medicines, novel therapies, and complementary and alternative medicine. Governments are actively taking efforts to eradicate this illness, such as mass media campaigns, raising public awareness, boosting health spending, and working with scientific specialists.

Post-COVID Syndrome| Long-COVID

Now that we're a year and a half into the COVID19 pandemic we're beginning to have an understanding of the lasting long-term effects the disease has. Prolonged symptoms have colloquially been called long-COVID and those who are experiencing these symptoms are colloquially called "Long haulers." Long COVID may also be referred to as "long term COVID, chronic COVID or Post-COVID syndrome," as no official term has been established yet. 

Although the majority of patients with COVID-19 recover within weeks after being unwell, some people develop Post-COVID symptoms. 

The term 

Post-COVID Syndrome

 is an 

umbrella term used to basically denote any symptoms arising right after the COVID infection.

It's important to remember that research on COVID19 and its prolonged effects on the body have only just begun. And to date we cannot draw any firm conclusions on the long-term effects of the disease. The studies highlighted here represent only initial findings and should be taken with a grain of salt. 

To begin researchers are discovering that long-term complications from COVID19 are fairly common. In October of 2020, the United Kingdom's National Institute for Health Research announced 10 to 20% of people who contracted COVID19 continue to have symptoms or complications of COVID19 one month after diagnosis. 

One study in Italy suggested 87 of patients infected with COVID19 continued to have persistent symptoms 60 days after their initial symptoms began. With the rising number of people experiencing long-term covid19 symptoms, the British National Institute for health and Care Excellence also called NICE, has categorized 3 unique stages of COVID19 recovery: 

1. The Acute COVID19 stage is the period of recovery within 4 weeks after diagnosis.  
2. The Ongoing COVID19 stage lasts 4 to 12 weeks after diagnosis.  
3. The Long COVID19 stage lasts over 12 weeks after diagnosis.

Some of the symptoms include:

• Chest tightness
• Cough
• Shortness of breath
• Fatigue 
• Lack of concentration

Fatigue is the most common symptom that 

appears to continue to persist after covid19 infection. A study in Ireland found over half of all patients continued to have persistent symptoms of fatigue 10 weeks after initial diagnosis regardless of how severe their initial symptoms were.

Cardiopulmonary issues such as shortness of breath cough and chest pain are also common. A study in the United Kingdom found 60% of patients admitted to general medicine floors and 72% of intensive care patients had continuing shortness of breath four to eight weeks after hospital discharge. 

Similarly a Chinese study found over 50 of patients performed worse on spirometry pulmonary function tests 30 days after discharge from the hospital.

Some less common but equally or sometimes more debilitating symptoms are:

• Mobility challenges (muscle & joint pains) 
• Palpitations (fast heart beats) 
• Dizziness 
• tingling/pains in fingers and toes 
• Sensory loss (hearing, vision, smell, taste, numbness)
• Memory loss
• Cognitive impairment
• Hair loss
• Anxiety 
• Depression 
• Headache 
• Skin rashes

Causes of long-term symptoms:

It's not clear if these symptoms are a 

continuation of the initial COVID19 infection or if they are related to an entirely new yet separate Post-COVID19 syndrome. There are however a few hypotheses that have been proposed which could be contributing to the prolongation of COVID19 symptoms. 

1. IMMUNE SYSTEM RESPONSE:

Some people's immune systems may respond to COVID19 more strongly than others weaker immune responses to COVID19 might lead to symptoms lasting several months instead of several weeks. Weak immune response can be caused by advanced age, pre-existing health conditions that impact the immune system such as HIV or possibly immunomodulating drugs such as steroids. 

On the other hand some people's immune response may be too strong. Their immune systems may become too aggressive in trying to fight COVID19 and as a result may cause cellular damage to other organs leading to acute respiratory distress syndrome and systemic inflammatory response syndrome. 

There has been some evidence that severe cases of COVID19 have been in part caused by a sudden and massive release of cytokines called a "cytokine storm" leading to significant tissue inflammation and organ damage.

2. RE-INFECTION: 

Re-infection with COVID19 may also explain persistent symptoms of the disease. Overall, it is unclear why so many people continue to experience COVID19 symptoms beyond the acute phase of the illness and we may not have a clear understanding of this for a few years. 

While the cause of these continuing COVID19 symptoms remains a mystery and there are no COVID19 specific treatment recommendations after acute infection.

-> If you observe any of these symptoms, you should observe following points immediately:

• Speak to your doctor immediately 
• Take the prescribed medication
• Rest and hydrate sufficiently
• Practice social distancing
• Hand hygiene 
• Use masks diligently

CAN POST-COVID SYNDROME BE PREVENTED?

The only way to prevent Post-COVID syndrome is to avoid COVID. For this following measures are crucial:

• Maintain social distancing and avoid crowds
• Practice excellent hand hygiene
• Avoid touching your face/ keep your face clean
• Use masks correctly
• Get your COVID vaccination as soon as you are eligible