by mark000
OPINION: The Covid-19 pandemic has already led to the infection of more than 3.5 million people and killed more than 250,000, so great hopes are being placed on the rapid development of an effective vaccine, with timelines of 12 to 18 months being touted. Science Minister Karen Andrews is even more optimistic, suggesting a vaccine may be possible within 10 to 15 months.
Australia has done remarkably well, thanks to the government’s prudent approach and the extraordinary efforts of our people to follow social distancing policies, with among the lowest rates of infection and deaths in the world, although each death is a tragedy.
Nevertheless, hopes for the rapid return to a normal life, here and worldwide, hinge on the development of an effective vaccine. But is this realistic and should we be paying more attention to developing a Plan B while we wait?
Vaccines are safe, relatively inexpensive and have been extraordinarily effective for many diseases, including smallpox, polio, chickenpox, yellow fever, hepatitis A, tetanus, measles, mumps, diphtheria, human papillomavirus that causes cervical cancer and even, most recently, Ebola. So why not for Covid-19?
There are more than 90 vaccines in development worldwide against SARS-CoV-2, the virus that causes Covid-19 disease. While these involve both traditional and novel approaches, all are based on the same premises regarding viral entry and host response.
I sincerely hope I’m wrong, but I suspect it is going to take many, many years to develop a vaccine, despite the extra $12 billion pledged into the search for vaccines, treatments and tests this week.
Findings from studies with SARS-CoV and MERS-CoV, both closely related to SARS-CoV-2, show that natural immunity to these viruses is short-lived. In fact, reinfection with the same strain that caused an initial infection has been observed in some animal studies. This raises the question: even if we are successful in developing a vaccine for Covid-19, for how long will it be effective?
There are also other reasons to be concerned. Successful vaccines provide protection by stimulating the production of so-called neutralising antibodies that prevent viral entry into cells. But despite years of work, vaccines have yet to be developed that can stimulate the production of neutralising antibodies effective against HIV, hepatitis C, cytomegalovirus or dengue fever, let alone SARS or MERS.
And certain viruses mutate rapidly, rendering the vaccine that was effective against last year’s flu virus, for example, ineffective against the strains causing infection this year. Rapid mutation may also mean that antibodies from patients who have recovered from Covid-19, so-called convalescent antibodies, may be ineffective for treating the disease in others who have an active Covid-19 infection, although trials of such antibodies, prepared by the CSIRO, are in progress.
Daily reminder.
There is more financial incentive for a company to develop a vaccine for the common cold than corona.
Yet no one has been able to develop a vaccine for the common cold.
Don’t get your hopes up. Any country planning on a vaccine is essentially praying at this point.