- Currently, four COVID-19 vaccines worldwide have 90% above efficacy
- We have made a lot of progress on the vaccine front: Dr. Swaminathan
- WHO awaits more efficacy and safety data on vaccines: Dr. Swaminathan
New Delhi: Scientists and pharmaceutical companies are working at a breakneck speed to develop a safe and efficient vaccine against coronavirus to fight the COVID-19 pandemic. In this mission, over 200 vaccines are being developed around the world by dozens of companies. Of these, four vaccines- Oxford-AstraZeneca’s AZD1222, Pfizer-BioNTech’s mRNA-BNT162, Moderna’s mRNA-1273 and Gamaleya Institute’s Sputnik V have exhibited efficacy in the rage of 90 per cent. This means that these vaccines are able to reduce the disease by over 90 per cent in a vaccinated group of people. While many are waiting to be injected soon, others are worried about putting something unknown in their bodies. To know if the vaccines that are ahead in the race of development, with a trial run on at least 20,000 people each, are safe to use, NDTV spoke to Dr. Soumya Swaminathan, Chief Scientist at World Health Organisation (WHO).
According to Dr. Swaminathan, while vaccine candidates showing more than 90 per cent efficacy is encouraging, these are based on the interim studies and there is a need to explore much more data. She said,
What we know about these vaccines is based on the interim data of the trials that these companies have performed and have released to the public. The complete data set will be submitted to the regulatory authorities as well as WHO for pre-qualification and that’s when we get to see all the data, including the safety data.
She further said that so far, there have been no major safety signals, in any of the trials the results have been presented from. However, she added,
But on the other hand, we have to remember that follow-up is really short. The clinical trials began July-August onwards, so, by the time participants were enrolled and received two doses of vaccine, they had a follow-up of only 1-2 months which is really not enough and the numbers are also relatively small. So, we need further follow-up and more data for both efficacy and safety. Currently, what we have is just the tip of an ice-berg. There is a lot that needs to be explored.
Dr. Swaminathan also commented on the unusual finding from Oxford-AstraZeneca’s vaccine trials where half dosage given as the first dose followed by a full second dose gives 90 per cent efficacy result whereas two full doses shows 62 per cent efficacy. She said,
The AstreZeneca data was released based on a very small number. It was from two different trials. It is quite unconventional to combine two different trials and come up with one efficacy estimate. That’s not the way it is usually done. The trial where they administer a half plus full dose had less than 3,000 participants and the total number of infections in that group was relatively limited. It is difficult to compare this small number of people with about 8,000 people in the other group where the participants were given two full doses. These are a really small number. So, I will say again that we need more data and that on a larger group of people. Because the variation in the data in the two kinds of dosage regime in two different trials can happen by chance as well.
However, Dr. Swaminathan highlighted that if the results of Oxford trials are true, then this would mean that maybe the half dose administered first act as a priming to the immune system and activates the T-Cells and then a bigger dose is given to the person which will give a strong immune response.
When asked about the safety concerns related to the four vaccines for children, she said,
Most of these vaccines have not been tested in children. They started with 18+ candidates because trials are always done in adults first. Some of the companies, however, have started going for trials among children in the age group 12-18 year and then they would further down to the younger children. So as of now, we don’t really have an answer about the safety of these vaccines as far as children as concerned.
On the distribution of vaccines and required infrastructure, Dr. Swaminathan said that candidates being developed by Pfizer and Moderna are based on a new technology which allows quick manufacturing of the vaccine but the disadvantage of such vaccines is that these need to be stored in extremely cold temperature because of the instability of these vaccines. While the Pfizer vaccine needs to be stored at -70 degree Celsius, Moderna’s vaccine needs -20 degree Celsius. So, this creates some logistical difficulties for many countries including high-income nations, she said. Dr. Swaminathan added,
Some companies are coming out with innovative solutions to maintain the temperature required for storing vaccines. For example, some are using dry-ice storage containers. But even that would be difficult because you need to ensure that you have enough dry-ice replacement capacity to keep cool enough. It lasts for about five days and then it needs to be replaced. So, I would say that it would be possible to use these vaccines, perhaps, in big cities and metros where the required facilities exist and can be used to vaccinate very high-risk groups like healthcare workers, frontline essential workers among others. But it will be very challenging to go beyond that and take it down to the district and below levels.
Dr. Swaminathan signed off saying that it is a big achievement for the scientific community to come up with technological breakthroughs and develop vaccines in a matter of 11 months since the novel coronavirus was discovered. It shows the power of science and technology today but there is a need to be extremely cautious and explore more data before the vaccines are rolled out, she said.
NDTV – Dettol Banega Swasth India campaign is an extension of the five-year-old Banega Swachh India initiative helmed by Campaign Ambassador Amitabh Bachchan. It aims to spread awareness about critical health issues facing the country. In wake of the current COVID-19 pandemic, the need for WASH (Water, Sanitation and Hygiene) is reaffirmed as handwashing is one of the ways to prevent Coronavirus infection and other diseases. The campaign highlights the importance of nutrition and healthcare for women and children to prevent maternal and child mortality, fight malnutrition, stunting, wasting, anaemia and disease prevention through vaccines. Importance of programmes like Public Distribution System (PDS), Mid-day Meal Scheme, POSHAN Abhiyan and the role of Aganwadis and ASHA workers are also covered. Only a Swachh or clean India where toilets are used and open defecation free (ODF) status achieved as part of the Swachh Bharat Abhiyan launched by Prime Minister Narendra Modi in 2014, can eradicate diseases like diahorrea and become a Swasth or healthy India. The campaign will continue to cover issues like air pollution, waste management, plastic ban, manual scavenging and sanitation workers and menstrual hygiene.[corona_data_new]