Hope and despair over variants and vaccines

COVID-19 is spreading again and becoming more genetically diverse. With every new infection, the coronavirus gets the chance to mutate, which then means more cases and deaths. The vaccines have entered the fray at a crucial time, within one year of the advent of the deadly virus. The fastest any vaccine had previously been developed, from viral sampling to approval, was four years, for mumps in the 1960s. It is tempting to hope that in the future, vaccines for variants might be made in a shorter time.

While scientists all over the world deserve to be applauded for bringing a vaccine so quickly and claiming it to be safe and effective, the birth of new mutants in different parts of the world is alarming. Should we produce a new vaccine with each new variant and get a jab afresh? Will it lead to a vicious cycle?

The second wave has seen a surge of new cases in the US, Europe and other countries. The recent increase in daily infections in India is also a worrying development. In such countries, as more people become infected, more replication cycles occur, with an increasing chance that an ‘escape variant’ resistant to vaccination and antiviral therapies will develop.

If there’s a confirmed jump in re-infections or if large numbers of vaccinated people start developing the disease, that’s when we will know whether escape variants have become a genuine new threat.

As of now, India’s vaccination programme is in full swing and over 3 crore people have been given the jab so far.

We have heard a lot about B.1.1.7 (UK), B.1.351 (South Africa), and P.1 (Brazil), but other variants have also emerged, including the one in New York. Named B.1.526, the variant contains the same E484K mutation that has caused concern over B.1.351. This mutation is presumed to allow the virus to partly escape the body’s immune response.

Vaccines developed against the original virus have also been found to be less effective against B.1.351. As per the March 2021 issue of the British Medical Journal, the variant was “surging, alarmingly, over the past few weeks” and that patients with this variant “were on average older and more frequently hospitalised’. Further analysis showed that the B.1.526 variant was “scattered in the northeast of the US, and its unique set of spike mutations may pose an antigenic challenge.”

Pfizer and Oxford-AstraZeneca are reported to be in discussions regarding updating their vaccines to target the new variants. Meanwhile, Moderna has said it is awaiting approval from regulators to start trial with a modified version of its vaccine that will target the B.1.351 variant.

The lack of data on B.1.351 cases means there is no information on vaccine effectiveness against this variant. Germany is facing hesitancy after a German newspaper reported that the vaccine was ineffective in people above 65 years. The Johnson & Johnson vaccine reported efficacy of 66.1 per cent for preventing moderate-to-severe or critical Covid-19, 28 days after vaccination of a single dose.

The two vaccines approved in India are claimed to be effective against the UK variant but there is no data on their efficacy against the mutants first found in South Africa and Brazil. It is difficult to say how effective the two will be against the new variants, until scientists study them properly and sound data is available.

Covaxin can produce antibodies against many regions of the complete virus, while Covishield produces antibodies against only a specific region of the virus. So, even if there is a mutation in one region, there are antibodies being produced against other regions of the virus which will be effective in case of Covaxin. It is an ‘inactivated’ vaccine developed by chemically treating coronavirus to make it incapable of reproduction. Scientists are in the process of developing booster jabs to tackle Covid-19 variants.

Should you take the vaccines despite reports of adverse events? The answer is yes. The US FDA’s Vaccines and Related Biological Products Advisory Committee voted 22-0 that benefits of the vaccine “outweigh its risks for use in individuals 18 years of age or older’, so the vaccine should qualify for FDA emergency use authorisation (EUA). Most members focused on the importance of getting out another vaccine against the virus, given the rising number of variants threatening to curtail progress against the pandemic.

The FDA staff noted that efficacy was lower among adults aged 60 years or older with co-morbidities versus healthier seniors. But the vaccine offered advantages like saving hospitalisations or deaths. N antibodies tend to fade after three-four months, but the S antibodies last longer, and those are the antibodies that the vaccines will coax the body into producing, so the results are directly comparable. In addition, you have a Covid-19-specific T-cell response after going through the infection. Even if the efficacy is low, vaccine use is recommended.

Should the very old and sick people also take a jab? Individuals with immune-compromised conditions may be eligible to receive the mRNA Covid-19 vaccine, but the safety data for such individuals is not available. Although HIV-positive patients were a part of the clinical trials, the vaccine’s safety and efficacy data in these individuals is not yet available. The vaccine may lead to a reduced immune response in immune-compromised individuals compared to the others.

People with autoimmune conditions are also eligible for an mRNA vaccine, but the safety and efficacy data in this specific group is also not available.

It is a big question whether the vaccines can trigger micro clot formation in those suffering from heart disease or diabetes and result in complications.

It is essential to inform the patients about these facts. A few patients who received an mRNA vaccine were reported to develop Bell’s palsy.

The following instructions should be mandatorily followed after vaccination — wear a mask; maintain six-foot distance from others; avoid get-togethers and crowds; wash hands with soap and water; sanitise hands using 60 per cent alcohol; and follow travel, quarantine, and workplace guidelines.