British-Swedish pharmaceutical company AstraZeneca’s large-scale human COVID-19 vaccine trial has been paused after one of the participants developed an unexplained illness. A spokesperson for AstraZeneca said the pause is “routine” and occurred when the firm’s standard review process was triggered. An independent committee will now review safety data pertaining to the trial. AstraZeneca stressed that an adverse reaction was only witnessed in one study participant, and that pausing trials was a common part of the vaccine development process. No details have been released about the nature of the participant’s illness, but it has been reported that the individual is expected to recover. Right now, all trials of the joint AstraZeneca-University of Oxford developed vaccine, AZD1222, have been halted worldwide, including in the United States, UK, Brazil, South Africa, and India. AZD1222 is one of three COVID-19 vaccines in late-stage Phase 3 trials in the United States. AstraZeneca and eight other drug makers have said they will not seek approval from US government regulators for any vaccine until all data showed it was safe and effective. All of the companies, which include Johnson & Johnson, Merck & Co, GlaxoSmithKline, Novavax Inc, Sanofi and BioNTech, said “the safety and well-being of vaccinated individuals” was their top priority.
With the number of confirmed COVID-19 cases worldwide now at more than 25 million, any news involving potential vaccines is important, which is why a recent announcement from AstraZeneca Plc is exciting. The British multinational pharmaceutical and biopharmaceutical company, which has its headquarters in Cambridge, England, says it has begun to enroll 30,000 participants aged above 18 in the United States for a large-scale human trial of its COVID-19 vaccine candidate, AZD1222. The US trial will evaluate whether the vaccine can prevent COVID-19 infection or keep the illness from becoming severe, the National Institutes of Health said in a statement. It also will assess if the vaccine can reduce incidence of emergency department visits due to COVID-19. AstraZeneca says the study is being funded by the US Government and that participants will either receive two doses of either AZD1222 or a saline control (a placebo), four weeks apart. The AstraZeneca shot, which has been developed by researchers from the University of Oxford, is one of the farthest along of numerous COVID-19 vaccines in development. As well as the US trial, a final-stage test of the vaccine is underway in the United Kingdom. Preliminary results from this test could be yielded as soon as next month. Other companies that have COVID-19 vaccines in phase 3 trials include Moderna Inc. and Pfizer Inc.
People who have recovered from COVID-19 and gained immunity to the disease could lose it again within months, a new study from the UK suggests. According to the research by a team from King’s College London, the novel coronavirus (SARS-CoV-2) could reinfect people year after year, much like common colds. Having studied the immune responses of more than 90 patients and healthcare workers at Guy’s and St Thomas’ NHS foundation trust, the researchers found that COVID-19 antibody levels peaked about three weeks after the onset of symptoms. [Related reading: Coronavirus: Immunity levels likely to be higher than antibody tests suggest] Blood tests revealed that while 60% of COVID-19 patients displayed a “potent” antibody response at the height of their battle with the disease, this figure fell to just 17% three months later. In some cases, antibody levels became undetectable. The findings of the study have implications when it comes to developing a COVID-19 vaccine, as well as achieving greater herd immunity. The bottom line is that if antibody levels drop over time and people are able to be reinfected seasonally, a vaccine would not actually provide any long-term benefits. Speaking about the findings of the study, Dr Katie Doores, lead author from King’s College London, said: “People are producing a reasonable antibody response to the virus, but it’s waning over a short period of time and depending on how high your peak is, that determines how long the antibodies are staying around.”
With the COVID-19 pandemic still causing chaos in many countries around the world, much focus has turned to developing a vaccine to prevent the horrible respiratory disease. But how far off is a coronavirus vaccine and what’s taking so long? At present, estimates on how long it will take to develop a safe, effective coronavirus vaccine range from one year to 18 months, with some experts warning it would take even longer. The reality is that in vaccine years that is extremely fast and the likelihood is that a coronavirus vaccine will take longer. Right now, no less than 35 companies and academic institutions are racing to develop a vaccine for the new coronavirus. At least four have candidates that they are currently testing in animals. One, produced by Boston-based biotech firm Moderna, will begin human trials very soon. One of the reasons why some companies had a head start creating a vaccine is because coronaviruses have caused two other recent epidemics: the 2002-2004 severe acute respiratory syndrome (SARS) outbreak in China and Middle East respiratory syndrome (MERS) outbreak, which was first identified in Saudi Arabia in 2012. In both cases, work began on vaccines, but these were later shelved when the outbreaks were contained. Some of those vaccines are now being repurposed to help in the fight against Sars-CoV-2 (the virus that causes COVID-19). Once a COVID-19 vaccine that is safe and effective in humans has been approved, another challenge will be producing it in the vast quantities needed. In the meantime, thoroughly wash your hands regularly and follow COVID-19 advice.