A tumultuous 2020 that upended how we lived our lives appears to be ending on a happier note with several countries beginning vaccination against coronavirus disease (Covid-19) in December. The news of the Sars-CoV2 variant in the UK that spreads faster is a dampener but virologists say so far it is not known to cause more severe disease and is unlikely to impact the effectiveness of existing vaccines, diagnostic tests, or treatments.
“There is no need to change the existing treatment protocol in view of mutations emerging in the strain. Further, since Indian Council of Medical Research (ICMR) has always advocated use of two or more gene assays for testing Sars-CoV-2, it is unlikely to miss infected cases using the current testing strategy,” concluded experts at the meeting of the National Task Force on Covid-19 on Saturday under co-chairs of Dr Vinod Paul, member Niti Aayog, and Dr Balram Bhargava, director general, ICMR.
India plans to begin vaccinating 300 million health workers, frontline workers and vulnerable populations as early as January next year, but vaccines do not signal the end of public health precautions for the vaccinated.
Reducing exposure to the virus by wearing masks, observing social distancing and frequently washing hands will remain the mainstay of social behaviour in 2021 and beyond, till everyone has been vaccinated against the disease that sickened at least 80 million and killed 1.75 million globally since the start of the pandemic in China last year.
Though not yet approved in India, all three approved vaccines– Pfizer-BioNTech, Moderna and AstraZeneca-Oxford – are given in two doses four weeks apart and it takes six to eight weeks after the initial dose to achieve the desired immunity for protection. So, those vaccinated will have to continue using behaviours that reduce their risk of exposure to the virus.
It’s still unknown how much protection Covid-19 vaccines provide in real-life conditions and for how long this protection lasts. What is known is that everyone can get vaccinated only by 2024. Since the herd immunity threshold for Covid-19 has not been established, we still cannot say how much of the world’s population will have to be vaccinated to stop the spread of infection to those who have not been vaccinated.
The effectiveness of the vaccine will also depend on whether it is stored and transported at optimal temperature. it will also depend on health of the recipients since the “warp speed” of development limited human trials data to mostly to healthy adults and those with stable pre-existing diseases.
Again, Covid-19 vaccines have only been tested for their ability to prevent infection and not for prevention of transmission. Most vaccines prevent infection and stop its spread, but some, like the annual flu vaccines, protect those vaccinated from severe disease but don’t always stop them from infecting unvaccinated people.
Vaccines train the body’s immune cells to the virus to prevent infection but how effective these immune cells are in crossing the mucous barrier to destroy the viruses resting in the nose is still unknown. If viruses in the nose remain viable, those vaccinated can shed them while speaking or sneezing to infect unvaccinated people in close contact.
Vaccines apart, a major upside of 2020 has been the demonstration of unparalleled heroism and resilience amid monumental adversity. Everyone did their bit. Health and frontline workers worked overtime in unsafe conditions to save lives, people stayed locked up at home for months to slow the spread of disease, children gave up school and play, jobless migrants trudged home for days and weeks to escape hunger, and scientists, industry, global agencies and nations forged unprecedented partnerships and worked overtime to make it possible to bring new treatments and vaccines to people within nine months.
As a result, the year that began on a sick note following the World Health Organization’s Country Office (WHO) in China discovering a statement about a mysterious “viral pneumonia” of unknown origin on the Wuhan Municipal Health Commission website on December 31, 2019, is ending with hope for a return to normalcy in the not-so-distant future.
The current wave in India appears to be waning, with the seven-day daily average for new infections staying below 25,000, down from a single day peak of 97,399 on September 10. Add to this results of antibodies surveys that indicate around 200-300 million have some degree of immunity against Sas-CoV2 and we have a momentum that can help get our derailed lives and economy on track by next summer. But this can happen only if we continue to take precautions and ensure the year-end holidays don’t turn into superspreading events.