With the results of last-stage clinical trials by two Covid-19 vaccine frontrunners — Moderna Inc and Pfizer — expected in the coming weeks, hopes have risen of securing an antidote to the novel coronavirus by December itself as infections surge across the United States and Europe with the onset of winter. Moreover, despite minor setbacks during Phase III trials in the past two months, the vaccine developed by University of Oxford and AstraZeneca Plc has produced immune responses in both elderly and young people.
However, the unprecedented pace at which Covid-19 vaccines are being developed — it can typically take 10 to 15 years to bring a vaccine to market — has led experts, including the UK Vaccine Taskforce, to say that the first generation of shots “is likely to be imperfect” and that “might not work for everyone”.
According to the World Health Organization (WHO), more than 150 Covid-19 vaccines are presently in development, with around 44 candidates in clinical trials and 11 undergoing late-stage testing.
Oxford-AstraZeneca coronavirus vaccine
In encouraging news, AstraZeneca said earlier this week that the AZD1222 or ChAdOx1 nCoV-19 vaccine candidate “has produced a robust immune response in older adults and the elderly, those at highest risk of severe illness”. The development is promising since older patients have been the hardest hit by Covid-19, with the majority of deaths occurring in those over 60, Bloomberg reported.
Trial participants aged 56 and over showed low-levels of adverse reactions. “It is encouraging to see immunogenicity responses were similar between older and younger adults and that reactogenicity was lower in older adults, where the Covid-19 disease severity is higher,” AstraZeneca said.
While AstraZeneca is aiming to launch the vaccine, made from a weakened version of a common cold virus that causes infections in chimpanzees, by end of the year, staff at a London hospital trust have been told to be ready to receive the first batches of the Oxford shot from November 2, The Sun newspaper reported.
In India, the vaccine, which is being tested by Serum Institute and named Covishield, may be ready as early as December, with the first batch of 100 million doses available by the second or third quarter of 2021, SII CEO Adar Poonawalla told NDTV.
This comes even as late-stage trials of the shot restarted in the US last week after it was halted since September 9 following one of the participants developing an “unexplained illness” in the UK. Earlier this month, a volunteer participating in a clinical trial of the Oxford vaccine died, triggering concern among the scientific community. However, AstraZeneca later said the participant didn’t receive the company’s shot.
Pfizer coronavirus vaccine
Pfizer, which had previously said that it could have vaccine efficacy data in October, expressed hope it could supply some 40 million doses in the United States this year if clinical testing proceeds as expected and regulators approve its single nucleoside-modified messenger RNA (modRNA) vaccine.
“We have reached the last mile here. If all goes well, we will be ready to distribute an initial number of doses,” AFP quoted Pfizer Chief Executive Albert Bourla as saying. Bourla said the firm still had not reached key benchmarks in assessing vaccine efficacy.
Moderna coronavirus vaccine
US-based Moderna Inc, which is expected to submit interim results of its mRNA-1273 vaccine trials next month, said a positive outcome could see the firm get US approval for emergency-use authorisation as early as December, according to a report in the Wall Street Journal. Moderna is eyeing to produce 20 million doses of its experimental vaccine by the end of the year.
Moreover, in a bid for a faster approval, Moderna has begun a rolling data submission of its vaccine candidate to the UK’s health regulator to start its independent assessment of evidence as and when it becomes available. Moderna has also applied for a similar real-time review of its vaccine in Canada.
Johnson & Johnson coronavirus vaccine
US pharmaceutical major Johnson & Johnson, which has resumed late-stage trials of its single-shot JNJ-78436735 in the United States following a pause due to safety concerns, recently announced that first batches of its candidate could be available for emergency use as soon as January. Initial results of the 60,000-person study is expected to be out by the end of the year. On October 18, trials for Janssen’s vaccine candidate, which uses a modified adenovirus like the Oxford shot, were put on pause after a participant developed an “unexplained illness”.
Sputnik V coronavirus vaccine
Nearly two months after becoming the first country to approve a Covid-19 vaccine amid scepticism from the scientific community, Russia has submitted applications to WHO for emergency-use listing (EUL) and prequalification of its Sputnik V vaccine. A prequalification nod will make the Russian vaccine eligible for worldwide access if they meet WHO standards of quality, safety and efficacy.
Last week, Dr Reddy’s Laboratories (DRL) received regulatory approval from the Drugs Controller General of India to conduct mid- to late-stage human trials of the Sputnik V vaccine candidate in India. Delhi-based Mankind Pharma is likely to market and distribute the Russian Covid-19 vaccine. The vaccine will be tested on around 1,500 participants across at least 10 sites, including those in Maharashtra, Andhra Pradesh and Telangana.