27 December 2021

It appeared to be a world that had a fix for the Pandemic when this year began. The Vaccine roll out had begun the last few days of the previous year in most parts of the world and with President Biden moving in to the White House, it appeared that the mandates and manufacturing bottle necks of vaccines would all be in the past, with a reasonable expectation that a vaccine coverage generated population cover would substitute for the elusive herd immunity in Covid19.

We now know what happened. The world was visited by multiple strains of Covid19, including three major variants of concern, the last one being Omicron. We know that significant sections of populations in Western Hemisphere became Vaccine Deniers, did not take up the offered vaccination and no mandate or missive could cajole them to offer themselves the jabs that could have made a vaccine based herd immunity possible. In many cases, the deniers were old anti vaxxers, but there were new groups adding to this one that has caused resurgence of diseases like measles which had once been conquered in the West. The new groups were largely driven by conspiracists, folk who felt that Covid19 was a bio terrorism or bio warfare or even one driven by vaccine Big Pharma. As speculation mounted using models, based on experience in Chile and Israel where 70% population was covered by two shots of available vaccine and still experienced break through infections, the evidence that infections were not stopped by immunisation and that only hospitalisation and death risk was significantly altered, meant that there was now grist to this mill. The biggest set back, is how the new variants showed reduced efficacy of antibody titres that showed up after being subjected to their presence, making a case for either a de novo new vaccine for the variant of concern or to use the existing vaccine as a booster. Studies were underway for both.

Firstly for governments this was a great dilemma especially for developing countries, since they are barely able to cope with coverage of their population, beginning with priority of age over 60, medical comorbidities segment, essential workers, before going to general population for whom vaccine was available. However, as a greater hurdle is how, only mRNA vaccines are available for whom this booster dose has been scientifically studied and agreed upon. So Canada authorises both Moderna and Pfizer, Singapore only Pfizer, in USA it is the choice between three authorised vaccines, two mRNA and the third is Johnson's vaccine which is similar to Sputnik V of Russia first dose which is Adenovirus 26(Ad26) vectored, with Sputnik Light which is only Ad26 as a single shot vaccine and similar to Johnson's vaccine, has reportedly been successful in boosting those who have received the Sputnik shots earlier against the Omicron variant. The EU has a unique experience of mix and match, where member countries have used many vaccines of both viral vector and mRNA type against the pandemic in their primary immunisation and recommend boosting too likewise. The mix and match strategy apparently causes more lasting and higher efficacy of vaccination induced immunity in target population.

India and China have vaccines that are based on neutralised virus of the Covid19 itself, as Covaxin and Coronavac by Sinovac. In India about 10% of all vaccinations given so far are from Covaxin while the majority is from AstraZeneca Oxford University stable which is locally called Covishield. A study in Hong Kong shows that boosting with Sinovac ( same as Covaxin) is not efficacious and people immunised with Sinovac are better boosted by Pfizer shot. So from all the date available in the public domain, boosting has been done with neither Covishield equivalent nor with Covaxin equivalent abroad. This suggests that either India has to ideally go for newer vaccine candidates to boost its population or import mRNA vaccines for the same. Naturally this vacuum of options has concerned even a popular newspaper to write an editorial based on the government's decision announced by PM Modi on Christmas Day to offer boosting...

I feel that third world countries should have waited before embarking on boosting programmes because the population at risk remains largely susceptible to existing strains far more than the Variant Of Concern(VOC). At any given moment so far, the pandemic has not shown a voc take over in these countries in contrast to its sweep of developed countries. The recent recovery from the new voc Omicron in South Africa again shows how the phase of a new variant runs its course in developing countries, which they have been able to weather far better than developed countries like UK, USA and Germany. If there is a bad advertisement for vaccination alone based strategy that has backfired spectacularly, it is Israel. Israel offered the third shot of Pfizer to vulnerable populations during the Delta wave itself... and now has decided to offer the 4th shot as booster to booster for protection against the Omicron variant! So sizeable population in Israel have had 4 shots in one year or less against Covid19, which shows that only vaccination as a strategy does not work without the support of non pharmaceutical measures.

If vaccines have efficacy issues, the monoclonal antibodies (MAB)that were successful against Covid 19 and which famously were used for President Trump last year ( Regeneron)have also lost efficacy against Omicron variant. Even Eli Lily's MAB doesn't work any more. Right now a MAB by Glaxo (Sotrovimab) has been reported to be efficacious enough and Evusheld by AstraZeneca shows promise. The drugs Paxlovid and Molnupiravir are said to be of some efficacy only when offered early enough (within 5 days of symptoms or onset), and in case of Paxlovid it must be combined with a retroviral drug ritonavir that is used against HIV.

So the cocktail of options and attendant supply chain issues while switching from one therapy to another, reveals how this pandemic calls for dedicated and consolidated research while being on the look out for new variants all the time. From how the boosting concept is getting under way, as policy, we can safely say that Covid 19 vaccinations and boosters will consume much of the already over stretched medical resources globally. In addition constant research by way of clinical trials and laboratory studies for efficacy will be needed not just for vaccines but also for MABs and drugs that are being used. Now after nearly two years against the pandemic, we can safely say that repurposed medicines have no role except for steroids in management of Covid patients. We can also safely say that cloth masks are not helpful nor are plain face shields. What works is surgical mask and N95 or FFP2 masks for Omicron variant.

Remember that old idiom that the sun does not rise to the call of the rooster? VOCs are inevitable whether we call them out or not in time, newer vaccine concepts beyond boosting strategy will see a place in 2022 if a new VOC beyond Omicron occurs which appears inevitable right now. So should countries rush for boosters or just wait for the new vaccine candidates that will offer immunity against variants? Probably. Should we as citizens hold our own against guidelines issued by public health authorities? No. The onus is on health authorities to make the right calls without getting swayed by public sentiment or political pressures to get back to 'normal'! Right now Taiwan again shows the way ahead by able leadership that is going about vaccinating its population as per its considered plan. The offer of booster is 'voluntary' and open to susceptible population as individually determined and as advised by their personal health advisers there. Taiwan has three vaccines on offer for boosting one indigenous(Medigen) and two imported mRNA vaccines (Pfizer and Moderna) even as it advocates a mixed vaccine strategy for primary vaccination. So it appears that populations with better leadership and more understanding of the vagaries this pandemic has imposed upon them would continue to do better against it, than those that are skeptical of science or those saddled with poor or populous leadership.

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