The Indian company Bharat Biotech (BB) on 3rd July 2021, released a press release about the final analysis for COVAXIN efficacy as part of phase 3 clinical trials after publishing preprint data on medRxiv. Here in this article we are comparing Phase 3 results of world’s 3 most popular COVID vaccines that are in vaccination drives around the world. 2 out of 3 got huge funding from international organizations for R&D and manufacturing and already have won Emergency Use Approval from WHO and FDA but Covaxin has to wait despite its high effectiveness and safety profile because it is from third world country.
It has been discussed in other articles of this issue that how the provenience of vaccine plays a role in approval through WHO and FDA. We have also seen in other articles from Biotech Express that how in COVID pandemics, the FDA and WHO have had become puppets of high impact journal like the Lancet and NEJM and changed their decisions toward COVID treatment in alternate manner when these studies were published and then retracted.
According to WHO and other health organizations, the vaccines are the most effective tool against the deadly coronavirus that is making fatalities around the world. From the very starting the world is trying to make a vaccine that can address various concerns regarding safety and efficacy but all the drugs and vaccines that are approved till now have come under scrutiny because they were contradicted by experts, some of them even banned for use and guidance was provided to not use them, the greatest example is HCQ. All have been objected except the Covaxin of Bharat Biotech which has not shown any severe side effects or deaths after vaccination.
We have seen the present condition of vaccine hesitancy and discussed separately in an article in this issue, that how despite having so many vaccines people are not willing to take them because they are not sure of trial results. Using a table we have articulated points that are destined to understand doubts about vaccine hesitancy in each vaccine and to check which vaccine can remove hesitancy from the minds of people all around the world.
Since the start of pandemic we have seen that every Chinese product has been questioned and subsequently rejected given the quality of products, for example the diagnostic kits which were rejected by several nations including India and Italy. Keeping this in mind the article has not included Chinese Sinovac’s CoronaVac, because its efficacy has been questioned recently in Indonesian population.
In current times, the most intriguing questions about COVID vaccine include safety, efficacy, effectiveness against variants, pregnancy, symptomatic efficacy, neutralization response etc. so we will discuss these points and try to find out the best vaccine.
Now coming to the most abundant vaccines that have been inoculated to masses till now are of Astrazeneca (ChAdOx1 nCoV-19), Pfizer (mRNA-1273) and Bharat Biotech (Covaxin). The former two released phase 3 results much earlier than latter.
To start with, though Astrazeneca has published results but still it is interim analysis whereas other two have published final results. None of the vaccine has considered vast racial and ethnic diversity.
Most importantly in current scenario after emerging variants, Covaxin group has studied the effects on variants specially the delta variant while other two have reported no studies in this respect. Pfizer currently asked WHO for booster dose for delta variant but Covaxin is ready for the same purpose without any additional cost and efforts.
Cost is an important factor to inoculate whole population, Astrazeneca’s vaccine in this respect can be a great worry as it requires booster dose for complete effect while other two do so in doses as described in trial results. Also Covaxin dose is very low so the manufacturing cost, and at the same time because the dose is low the chances of allergic reactions or side effects are also negligible.
The storage of vaccine is great for COVAXIN and Astrazeneca but because the conditions are stringent for Pfizer, the cost of maintaining the lots and the chances of wastage are also high.
Vaccine manufacturing lots consistency was questioned worldwide after it was found that Pfizer’s mRNA concentration was different in the supplied vaccine as compared to trial vaccine, as per the leaked documents analyzed by BMJ. Covaxin is the only vaccine that has considered manufacturing lot consistency and so each vial has the same material and as much safe as the material used in trials.
When we talk about the vaccine trial conditions, the COVAXIN has recruited largest number of participants as well as done studies to the longest time to see the post vaccination effects. It also considered pregnancy related studies in females whereas other two did not. Covaxin and Pfizer also considered subjects at risk whereas data for the same is not available for Astrazeneca’s vaccine, lack of this data does not tell us that how this vaccine works against serious cases.
To study the effect of vaccine it is important to know how many subjects still got the disease after the therapy i.e the safety of vaccine. In Covaxin the number of subjects who got symptomatic after vaccine is far less than the other two in both patient group as well as the placebo. The higher number of symptomatic cases in placebo group in comparison to patient group after vaccination, showed that vaccine prevented the COVID symptoms.
The overall Efficacy of Covaxin lies between Astrazeneca’s and Pfizer vaccines but the efficacy in severe cases which is real efficacy of vaccine is shown only in Covaxin and not other two, it is 93.4% in Covaxin group and thus it can prevent serious COVID cases.
What will happen to future immunity against virus, it is not sure in Astrazeneca’s and Pfizer vaccines because both other two have not done studies to see the effect whereas Covaxin has shown that it produces neutralizing antibodies that provide long term immunity against virus so there is no need of further expenses to get booster dose in future.
Serious adverse events were also reported in Astra and Pfizer vaccine like Anaphylaxis, Transverse Myelitis Myocardial Infarction, Cholecystitis, Nephrolithiasis, Bell’s Palsy that if not considered for further studies can lead to wipe out of huge population or long term effects on health. Covaxin in this respect has been proved as safe because it reported no side effects after vaccination.
From the above discussion it is easy to conclude that though Covaxin was little late in doing studies and producing little doses than others but it has come out as the safest and most effective vaccine on several parameters that were not considered by other vaccine producers. It is an answer to people who are showing vaccine hesitancy. It is manufactured in safe environment and so the chances of contamination are negligible. If we set aside the politics, the WHO should approve this product for the benefit of human race and international funding agencies should fund Bharat Biotech to increase the manufacturing capacity of COVAXIN as the delta variant is again emerging and the cases are rising in USA and other countries. We have seen that none of the vaccine is effective against delta variant and thus Covaxin is the only choice the world has to save its people.
Published in July 2021 Issue