Covid Around 90 crore of India’s adult population is eligible for Covid vaccination in the third phase, and if even half of them is vaccinated, it will take till the end of the year with 40 lakh vaccinations being done each day.
With vaccination, that effective protection starts at least two weeks after the second dose. However, there is a tendency among some people to lower their guard after the first dose itself (Peltzman effect), which can not only cause them to get infected but also make them inadvertently transmit it to others if they are asymptomatic. Another issue plaguing many people was the reluctance to get the vaccine. To allay vaccine hesitancy, we should generate local data on adverse effects. We have to cut vaccine wastage as well by using the last drop in the vial.
Viruses constantly change due to changes in their genetic structure resulting in mutations and variants that carry the risk of increased transmission, increased severity or poor response to vaccination. The US CDC has classified these variants as Variant of Interest, Variant of Concern (VOC), and Variant of High Consequence. Some of these variants are: B.1.1.7 (US), B.1.351 (South Africa), P.1 (Brazil),and B.1.427 and B.1.429 (California).
The Indian SARS-CoV-2 Genomic Consortium found “A new double mutant variant” which carried features from two worrisome lineages; the variants first identified in California and those discovered in South Africa and Brazil. This new variant, B.1.617, has been declared a VOC recently by the US and the UK and has three further subtypes. In India, different variants are predominant in different regions and states, the UK variant in Punjab, double variant in Maharashtra and Karnataka, and the South African variant in Telangana. Scientists say that the recent surge can partly be explained by the emergence of new variants. A recent ICMR study has shown that the Indian variant led to increased severity of infection as compared to B.1, the first dominant variant of the virus, in animal experiments.
There has been an apprehension that mutants may lead to lack of efficacy of vaccines, but so far, the available vaccines are effective against the commonly encountered mutations. However, there is a need to closely monitor the emergence of new variants by genomic studies to pre-empt their consequences.
We have to treat the infected patients with concerted efforts, and secondly, prevent the disease and break the transmission by vaccinating 60-70% of our population.
The ICMR recently issued guidelines for treatment of mild, moderate and severe cases. These clearly define that mild patients can be treated in home isolation, and that when oxygen levels drop below 94%, patients need consultation of a doctor. The use of different modes of supplementing oxygen and drugs like Remdesivir are clearly laid out. If these guidelines are followed strictly, our limited resources can be utilised optimally and patient outcomes can improve. Currently, there is lack of understanding among some medical personnel about the right indications of using different drugs and even tests and CT scans. There is a need to disseminate the treatment protocol widely, especially among doctors in smaller hospitals. At the same time, it needs to be reiterated that people should not panic or hoard drugs and oxygen at home.
Apart from Covid-appropriate behaviour (mask, social distancing, hygiene) the most effective way of preventing Covid-19 is the vaccine. The Spanish flu had continued to torment the world as there was no effective treatment or a vaccine.
Today, we have a number of vaccines, with all being 80-95% efficacious. India has already vaccinated over 17 crore individuals with 3 crore getting both the doses.
Experience from across the world has shown that large-scale vaccination is the only way to open business, economy and travel. While 2.3% of India’s population has been fully vaccinated till the first week of May, the corresponding figures for full vaccination in Israel, the UK and the US are 56%, 33% and 24%.
A recent article from Israel in The Lancet has shown that two doses of Pfizer-BioNTech vaccine provided more than 95% protection against Covid-19 infection, hospitalisation and death. It is the effect of vaccination only that cities in the US, UK, Israel and many European countries are reverting back to normal life. Vaccine certificate or “Vaccine Passport” is required to travel in many countries now.
We hope the second Covid wave will flatten soon, with statistical modelling predicting a peak in mid-May. However, there will still remain the prospect of a third wave till enough herd immunity is generated with enough vaccination. For that, we have to rely on preventing person-to-person transmission by enforcing social distancing and using masks. The virus is transmitted by droplets as well as through aerosols. The latter mechanism calls for precautions to be taken even when indoors. A cloth mask of two or more layers should be used and it should cover the mouth and nose snugly.
(Dr Naresh Purohit is a Medical Expert and Advisor National Communicable Disease Control Programme. He is also Advisor to six other National Health Programmes. He is visiting Professor in five Medical Universities of Southern India including Thrissur based Kerala University of Health Sciences. (The views and opinion expressed in this article are those of the author)