Vaccination, precautions can help rein in Covid

INDIA is in the throes of a rampaging second wave of Covid-19. Currently, India accounts for nearly half of the daily cases across the world and one-fourth of the deaths. Corresponding to these figures is the grim fact that test positivity is around 20%, with some states recording over 30%. The second wave is far more intense than the first one, when the maximum single-day caseload was slightly over 97,000.

Other countries have also had multiple waves since the onset of the pandemic in January 2020. The US has had three waves, in April and July 2020, and January 2021 with the third being the most deadly; England has had three waves in April and October-November 2020 and January 2021 with the third wave being the most severe. A century ago, the Spanish flu, caused by the H1N1 influenza-A virus had four waves, with the second wave the most deadly. Though not studied at the time of the Spanish flu, the deadly second wave was attributed to variants of the H1N1 virus.

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.

Around 90 crore of India’s adult population is eligible for vaccination in the third phase, and if we aim to vaccinate even half of them, it will take till the end of the year with 40 lakh vaccinations being done each day. It is important to realise that effective protection after vaccination 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.

We hope the second 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. It has been proven now that 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. The US Centre for Disease Control in its Morbidity and Mortality Weekly Report (February 19, 2021) has shown that double masking is superior to a single mask. A cloth mask over a surgical mask protected to nearly 90%. It must also be emphasised that cloth masks have to be washed regularly, and surgical or N95 masks be disposed of after every use; and a loose handkerchief and a bandana are poor substitutes for masks. Some studies even suggest that masks might reduce the severity of infection by decreasing the inoculum load.

We, therefore, need to reinvigorate ourselves in our fight against the virus. People should follow Covid-appropriate norms strictly and go for the vaccine when their turn comes. This will also help reduce the magnitude of the postulated third wave in the coming months.