The first-generation of vaccines to fight the Covid-19 infection may not be perfect and may not work for everyone, said Kate Bingham, the chair of the UK government’s Vaccine Taskforce.

“No vaccine in the history of medicine has been as eagerly anticipated as that to protect against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2),” Bingham wrote in medical journal The Lancet on Tuesday. “Vaccination is widely regarded as the only true exit strategy from the pandemic that is currently spreading globally.”

However, she added, that we do not know if there will be a vaccine at all. “It is important to guard against complacency and over-optimism,” she said. “The first generation of vaccines is likely to be imperfect, and we should be prepared that they might not prevent infection but rather reduce symptoms, and, even then, might not work for everyone or for long.”

Globally, the coronavirus has infected more than 4.39 crore people and killed 11,66,127, according to the Johns Hopkins University. Worldwide recoveries have crossed 2.97 crore. India’s coronavirus tally rose to 79,90,322 and the toll increased to 1,20,010 on Wednesday, while the UK has recorded 9,20,664 cases of the coronavirus and 45,455 deaths so far.

Bingham said that the taskforce’s strategy has been to build a diverse portfolio across several formats to ensure “the greatest chance of providing a safe and effective vaccine, recognising that many, and possibly all, of these vaccines could fail”. Their focus has been on people older than 65 as most deaths caused by Covid-19 have been in this group.

She added that international co-operation was vital as the pandemic was a global one with a toll of over 1.1 million deaths. “No one is safe until we are all safe,” she wrote. “Pandemic viruses do not respect national borders.”

Bingham added:

“There will not be one successful vaccine, or one single country, that is able to supply the world. We urgently need international cooperation to pool risks and costs, address barriers to access, and scale up the manufacturing capacity to produce sufficient doses to protect everyone at risk of SARS-CoV-2 infection globally.

The SARS-CoV-2 virus is likely to evolve, and other zoonotic pathogens are likely to pose future risks. China, Europe, the USA, and the UK need to work together. If we establish international collaboration right now, then we will be better prepared to control future pandemics without causing the largest global recession in history and the biggest threat to lives in living memory.”

— Kate Bingham in 'The Lancet'

Over 100 vaccines are being developed around the world to tackle the coronavirus pandemic. A vaccine developed by the University of Oxford and British-Swedish pharmaceutical company AstraZeneca has been widely seen as one of the leading candidates against the infection.

AstraZeneca on Monday said that its vaccine produces an immune response in both old and young adults. The vaccine also triggers lower adverse responses among the elderly, the pharmaceutical company said. The statement is significant as age is considered a principal factor when developing a Covid-19 vaccine.

In India, Hyderabad-based firm Bharat Biotech has said that its coronavirus vaccine candidate, Covaxin, is likely to be ready for launch by June. The firm received go-ahead for phase 3 clinical trials last week. Covaxin, India’s first indigenous vaccine, is an inactivated vaccine created from a strain of the infectious SARS-CoV-2 virus. Inactivated vaccines use the killed version of the germ that causes a disease. It helps the immune system mount an antibody response towards virus. It has been developed in collaboration with the Indian Council of Medical Research.