 Hello and welcome to NewsClick to our weekly COVID show. We are joined by Dr. Satyajit Rath. Thank you for joining us, Dr. Satyajit. So today we want to start with the recently released efficacy data of our Indian vaccine Covaxin, something which we have been waiting for for a long time. The makers of the vaccine have said that this, that the interim efficacy of this vaccination is 80.6%. Now Covaxin has been, we have been administering it since January. Brazil might also be soon buying up 20 million doses of this and it's also set to go in a few other countries. But so what does this term mean, interim efficacy? Can you tell us about this? Can you tell us about how this effectiveness has been measured? Yeah, so let's keep in mind something that we've discussed earlier, which is that all vaccines in human trials go through three phases. So phase one and phase two are safety and immunogenicity trials, meaning that they are trials that together establish that the vaccines are safe with no awful consequences and that they generate immune responses in everybody who gets them, generate sort of antibody responses that look as though they would be protective. The phase three clinical trial on the other hand is actually a trial to see whether they really do protect. So typically for all COVID-19 vaccines over the past year ever since last May or so when the Moderna trials started, what's been done very broadly is 10,000 people unvaccinated, 10,000 people given this vaccine candidate. And then after the vaccine administration is over, in both groups, you start counting the number of symptomatic COVID-19 cases that occur. And once you have a reasonable number of cases in the unvaccinated group, you ask, how many did you get in the vaccinated group? And the difference between those two numbers is the degree of protection that gets reported. So we have seen these numbers 92%, 95%, 92.5%, 81%, 62%, 70, whatever, or 80, 81% in Covaxin's case. All of these numbers are simply the calculation of the number of cases in the unvaccinated group versus the smaller number of cases in the vaccinated group. And that reduction is the percent efficacy that's being talked about as a number. So there are two major limitations with these data. So let's first remind ourselves what these data do tell us. They do tell us that these vaccines show reasonable protection. However, what they don't tell us is two things. Number one, they don't tell us what these numbers are going to look like at the end of the clinical trial because these are interim data. These are preliminary data. Clinical trials for these vaccines typically are designed to last for a year. So none of the vaccines have had their clinical trial, phase three clinical trials completed, which is why none of the approvals anywhere in the world for any vaccine is a regular regulatory approval. It is all emergency use authorization based on these early data. These early data therefore are not necessarily telling us what the percentage protection will be at the end of the clinical trial. Number one, number two, because these early data are typically within the first two, three, four months of the trial, they don't tell us with any great reliability how long a protection is likely to last. So both of these missing pieces we will get when the trials begin to be completed after running for about a year or so. So in the meanwhile, these are really interim efficacy data based on which emergency use authorizations are done. For co-vaccine, no such data were available for the past month and a half. And yet the Indian regulatory authorities accorded approval and therefore the co-vaccine approval for deployment was not just a simple emergency use authorization such as was given for co-visual. Instead, it was an approval in clinical trial mode. Now, as we've discussed, did I think that co-vaccine was not going to work? No, I thought in common with everybody else that it would work. Part of the reason for that is that a very similar design of a Chinese made vaccine inactivated whole virus vaccine had already been shown to work. So there's no reason to think that it wouldn't work. It was shown to be safe. It was shown to be energetic. However, regulatory approval without even preliminary efficacy data meant in clinical trial mode, which meant, as we've discussed, that everybody who has been getting a vaccine so far has to sign a consent form. One hopes and presumes that the prime minister has signed the consent form. But what that meant was that everybody who's getting it is volunteering to be participating in the clinical trial. And that volunteer status is ethical only if there is the option to refuse. It has to be voluntary. But if people are told that if you don't sign the consent form, you won't get any vaccine that has begun to verge on the coercive. Now that these data have apparently been obtained, this is simply a press release that we're dealing with at the moment, presumably the regulatory authorities will see the data, will examine the data and will convert to the clinical trial mode approval into a regular emergency use authorization. Let's keep in mind that these data, in these data, what has been reported, the numbers are at the lower end of the general spectrum. There's 36 cases in the unvaccinated group. I think that's pretty low. Although there are a couple of other vaccines also for whom, for which the numbers are similarly low. So this is the background. The hope is that we will now shift to emergency use authorization. We will stop trying to get people to sign consent forms and we can move on from the premature, aggressive vaccine nationalism into a substantive addressing of the kind of work that we have to do to bring the pandemic into control. Okay. So can you also give us a general update on the situation of vaccines right now? We have, what new ones have been approved? What ones are we expecting to see in the future? What is their efficacy like? So can you tell us about that? So steadily vaccines are coming up for approval. So a Janssen and Johnson vaccine, and I tend to insist on this a little pedantically because the vaccine was actually developed by a small company called Janssen. Johnson and Johnson are the multinational funder company. So the Janssen, Johnson, Johnson vaccine, which is an adenovirus based vaccine like Covishield, except that it was designed as a single dose vaccine which has enormous logistical advantage has just been approved in the United States. There are, one gathers that there are bridging trials, meaning phase one and phase two trials going on in India. And if that's correct, then we can look forward to having that approved. Novavax, which is not based on any of these RNA, DNA or virus vector, but is straightforward spike protein of the virus with adjuvant injected and you make antibodies in the old fashioned way, has shown efficacy and is under consideration and is likely to be approved. And again, there are bridging trials that have been reported to be on in India. So that's yet another vaccine that will be coming up in the short term in the near future. My guess is that over the next two months, we are going to start seeing more and more and more vaccines coming up. And that's going to change the logistical landscape of vaccination campaigns for COVID-19 quite dramatically. As we saw, as soon as the Janssen, J&J vaccine was approved by the US FDA, the US federal government has made arrangements such that the US president announced originally that the US would have enough vaccines to cover its entire population by the end of July with the new approval, he's brought that date forward to the end of May. And that's what's going to happen. It is going to complicate matters as well because it's a matter of who gets which vaccine, what is the schedule of vaccine delivery, where can it be delivered, which vaccine is to be delivered, where this is going to be an absolute nightmare to organize. And I hope that our health administrative system and framework is going to be up to the task. What has happened over the past two, three days in implementing the larger expanded vaccination campaign for the above 60s and the above 45s with comorbidities makes one worry, but let us hope that it will work. And when we talk about the efficacy of these vaccines, so Johnson and Johnson is reported to be around 72% effective overall in the initial trials that have been carried out. But it's also, and then when we compare it to Moderna and Pfizer, it was reported the approximately 95% effective. But then it's also being pointed out now that there's also a difference here because Moderna and Pfizer trials were conducted over the summer when these new variants were contagious variants were not present and Johnson and Johnson has been tested out now. So how does that compute in all of this? Right. So in the first place, none of these numbers, as I will never tire of pointing out, are reliable numbers. They are based on preliminary data. They're really not real numbers in the precise sense. All that they say is that the vaccine shows reasonable efficacy, good enough to administer to people. This is the first point. The second point is while it is true that the Moderna and Pfizer trials took place six, seven months ago and therefore are based on data from a time when the virus population was more homogeneous. And now clearly the virus population is getting more and more heterogeneous as the epidemic progresses. Nonetheless, the evidence that the antibody profiles generated by different vaccines is substantially different particularly with regard to protection against variants, variants of concern as they are called, that evidence is really very thin. So at this point, all we can say is that all vaccines will work with reasonable, will provide reasonable protection against the collection of original strains or the collection of original variants and that even against some of the emerging variants, they seem to show respectable protection against P1.7, for example, pretty much all of them seem to show respectable protection. Whether the reduction in the degree of protection that they show against a substantially altered variant such as the P1 variant that has been reported from South America and reluctant to use the term resilient against the P1 variant that has been reported originally from South America, whether that reduction in protective ability of the antibodies is sufficient to have public health consequences in terms of allowing infection to spread in the community and or in allowing people who have been infected earlier with an original strain to be reinfected or not is still quite unclear. The epidemiological data that are being talked about in this respect from the city of Manaus in the Amazonia in Brazil seem to indicate that despite having had a large proportion of the city's population, antibody positive by October or so, Manaus is seeing a new surge in cases. Is there reason to be concerned? Yes, there is. Is there reason to panic? No, not simply because there is never any good coming out of panic, but also because the Manaus data, which is really at the center of this concern, that evidence is very indirect. It says that by October 60, 70% of the population of Manaus in Brazil appeared to have antibodies against the original SARS-CoV-2 virus. And yet over the past month or two, case numbers have risen and many of those cases are against with the P1 variant of the strain. And then interpretation that has been offered is that reinfection with the P1 variant is possible even in people who have experienced previous SARS-CoV-2 infection and would be expected to be immune to it. All of this is still early days of evidence. And my guess is that what we are nonetheless going to see is that very serious illnesses as a consequence of infection are still going to be reduced by either naturally infection with the original strains and or vaccination with the present first generation vaccines. Thank you Dr. Satyajit for joining us today in this session. We'll come back to you next week and continue our updates. That's all the time we have today. Keep watching on this clip.