Vaccinated people better protected against Covid but can still transmit diseases: experts | MorungExpress

New Delhi: A five-star hotel employee receives a dose of COVID-19 vaccine in New Delhi on Monday, April 12, 2021. The hospitality industry has been hit hard due to the ongoing COVID-19 pandemic. (PTI Photo / Kamal Kishore)

New Delhi, April 12 (PTI) COVID-19 vaccines protect against serious illness, but transmissibility can continue and those inoculated can pass the infection on to others, say scientists, warning of complacency by those who stop maintaining the protocol after having received their injections.

Communicability of those vaccinated may be a risk factor until global coverage is reached, leading experts said as the number of Covid people in India rose sharply, reaching 1.35,27,717 (1.35 crore / 13.5 million) with 168,912 new cases on Monday. it is the country with the second highest number of cases after the United States.

“Vaccination is just one of the many different strategies we face during the pandemic. However, this is not a magic one-stop-shop solution, ”immunologist Satyajit Rath, from the National Institute of Immunology in New Delhi, told PTI.

“None of the vaccines currently available offer protection against transmission of the virus. Statistically speaking, the infection after the vaccination is likely to be milder than the one without, ”added Vineeta Bal, an immunologist at the Indian Institute of Science, Education and Research in Pune.

As researchers around the world try to understand how well COVID-19 vaccines prevent those vaccinated from passing the virus to others, experts have stressed the need for masks and physical distancing regardless of vaccination status . This must continue until the majority of people are vaccinated.

Scientists also fought for universal vaccination, saying it would provide strong community resistance to severe local epidemics. Warning against lowering the guard even after vaccination, they said some people who get vaccinated early may lose their immunological memory over time and become vulnerable again.

“Vaccination remains individual protection, not community protection, until we reach near global immunization coverage. It is possible that vaccine-resistant virus variants will emerge, requiring constant vigilance and the rapid development-deployment of next-generation vaccines, ”said Rath.

Bal agreed that the severity of the disease will be low in those vaccinated compared to those unvaccinated.
“This is presumably true even with virus variants. Therefore, being vaccinated is a better state of affairs at the population level as well as individually, ”Bal told PTI.

Rath noted that if an individual is effectively vaccinated, meaning they develop robust and long-lasting levels of neutralizing antibodies, reinfection with vaccine-susceptible strains of SARS-CoV-2, even if this does occur, is likely to be associated with mild illness.

On the flip side, he said, a new infection with vaccine-resistant strains of SARS-CoV-2 could still cause serious illness in some cases.

“So yes, vaccinated people could still transmit the infection, although the probability and dose transmitted would be lower. Of course, if they are infected with a future vaccine resistant strain of virus, then effective transmission could occur, ”he explained.

The vaccination campaign in India was launched on January 16 and healthcare workers (HCWs) were vaccinated. On February 2, the vaccination of frontline workers (field workers) began. . On March 1, the vaccination net was extended to people over 60 and people aged 45 and over with specified co-morbidities. A month later, on April 1, the vaccination was opened for all people over the age of 45.

While several circles have called for the age limit for COVID-19 vaccination to be relaxed given the increase in the number of cases, the Center said last week that the goal was to protect the most vulnerable and not “to administer the vaccine to those who want it, but to those who need it”.

“The fundamental goal is to reduce mortality through vaccination. The other goal is to protect your health system,” Union Health Secretary Rajesh Bhushan told a press conference. weekly.

He later clarified his remark, saying the government was following a model of dynamic supply and demand mapping.

Last month, Union Health Minister Harsh Vardhan said that “not every vaccine requires universal vaccination and all of these priority groups that we are vaccinating today like health workers first, then the elderly and people aged between 45 and 59 years, it will be extended in the coming days – all this is based on expert opinion ”.

According to Rath, the idea behind this strategy is “herd immunity”, where the cycle of transmission of the virus is interrupted if enough people are effectively vaccinated. And as a result, even unvaccinated people are no longer infected, simply because the virus is no longer there.

“The problem is, we don’t have a very reliable idea of ​​what percentage of the community needs to be vaccinated for effective ‘herd immunity’ against SARS-CoV-2. It is therefore difficult to see what this government assertion is for in practical terms, ”he added.

The scientist explained that universal vaccination would be “good” because it would provide very strong community resistance to severe local epidemics.

Bal added that vaccinating almost everyone would be a good thing in an ideal situation. However, strong safety data on pregnant women is not available for every vaccine, and most vaccines are not tested on children under 12 years of age.

“Therefore, direct recommendation for these categories of people is difficult to do. Although I believe that vaccines made using older platforms such as killed vaccines or pure protein vaccines compared to mRNA vaccines for example can be considered safe based on past experiences ” , she added.

Vaccines generate immunity by mimicking a milder form of an infection and helping the immune system “remember” the pathogen. They therefore contain part of an infectious agent capable of generating an immune response, such as viral genetic material, its RNA or DNA, or virus proteins which interact with human cells.

If there are vaccines, and if they can be paid for, it’s okay to aim for universal immunization, Bal said.

“Because when this level is reached, some people who have been vaccinated early may lose their immunological memory and become vulnerable again. We do not yet know how long vaccine immunity will last against SARS-CoV2, ”she added.

The two vaccines currently approved in India are Covishield, from the Oxford / AstraZeneca stable manufactured by Pune’s Serum Institute of India, and Covaxin, developed by Bharat Biotech, based in Hyderabad, in collaboration with the Indian Council for Medical Research and the National Institute of Virology (NIV).

On Monday, an expert panel from India’s Central Medicines Authority recommended approval of Russia’s Sputnik V for emergency use under certain conditions.