If the Pfizer/BioNTech and Moderna vaccines pass their remaining regulatory tests and are followed by others as immunologists expect, there could be a substantial vaccination programme under way early in the new year. This will fight off the virus should those vaccinated be infected, and there is optimism that they could also be unable to infect others. If sufficient numbers take a vaccine which protects a high percentage of those who take it, the population can reach herd immunity, where the epidemic begins to die out for want of sufficient people remaining susceptible to infection.
Most of those who catch COVID-19 recover and cease to be infective after some weeks, or a few months in more serious cases.
These first vaccine announcements are milestones and there will be further results in the weeks ahead
They become immune, although there have been some rare incidents of reinfection. This, plus immunisation through vaccines, could bring the pandemic phase to a close in the year 2021, even if the disease is not completely eradicated.
These first vaccine announcements are milestones and there will be further results in the weeks ahead.
Whether the uptake of approved vaccines delivers enough immunity in the population depends on four factors:
The percentage of vaccine recipients who are protected. For the Pfizer/BioNTech discovery, the preliminary figure is 90%, for Moderna 94.5%. The percentage of the population who take the vaccine.Any additional percentage who have become immune after recovery from infection. The percentage threshold for herd immunity.Most experts believe that the disease will begin to die out once 60% or 70% of the population have attained immunity, either through taking a vaccine or through infection and recovery. But it depends on behaviour – if people observe strict social distancing indefinitely, herd immunity would be attainable at a lower threshold.
If there were no public health policy at all, the let-it-rip approach with no vaccine, herd immunity could require a threshold of 90% or even higher, after much illness and a horrendous toll of deaths.
If vaccination proves to be 90% effective, better than the pre-trial expectations, this would be great news. With, say, 70% of the population opting for vaccination, 63% (0.9 times 0.7) would become immune and hopefully non-infectious. Add another 2% or 3% for immunity from the infected-but-recovered group and you get right into the range where herd immunity (plus some continuing careful behaviour) would be sufficient to end the epidemic.
How many people in Ireland would take the vaccine, assuming it would be entirely voluntary? The polling company IPSOS/MRBI reported these figures recently, before the good news from Pfizer/BioNTech was released (Figure 1).
Pessimistic
Some of the news media reported the story along the lines of “only 55% will take vaccine” but this seems too pessimistic. If half of the “not sures” decide to do so, just over 70% would oblige and immunity could be high enough to stop the epidemic.
Sentiment could also tilt towards compliance as the positive vaccine stories emerge in the coming months.
Some employers, for example in the health sector and in public transport, could require employees to vaccinate and the public could exhibit a preference for retail outlets able to advertise “all staff have been vaccinated”. The anti-vax lobby groups include some conspiracy theorists who can expect a rough ride in the media but there are also people with understandable concerns about any new vaccine.
The Government and the pharmaceutical industry will need to engage transparently with this group and to listen to genuine concerns. The nature and scale of the safety trials currently under way needs to be explained.
It is now clear that the failure to institute proper testing at airports and seaports has been a weakness in the Irish response to COVID-19.
During the summer, Nphet ascribed very few cases to the category “travel” even though there is definitive evidence that a strain of the virus uniquely traceable to Spain showed up around northern Europe, including Ireland, courtesy of returning holidaymakers.
The public health experts have changed their tune about travel
Propagation from this source was instead identified as “community transmission”, Nphet-speak for “we do not know”.
The public health experts have changed their tune about travel and have expressed the fear that travel over Christmas, especially from high-incidence countries such as the United Kingdom, could undo whatever is achieved through the second lockdown.
Relaxing lockdown for Christmas will be easy. The risk is that it will return
Testing systems were introduced at several European airports as long ago as June and the complacency of Nphet about travel during the summer may help to explain the Irish delay.
International airlines and travel industry lobby groups insist that rapid antigen tests, even if they give some false negatives, are preferable to the slower, and more expensive, PCR tests of which Irish health officials appear curiously enamoured.
Relaxing lockdown for Christmas will be easy. The risk is that it will return for Valentine’s Day before vaccination gets going.
Read more
COVID-19 transforms food consumption
COVID-19 collapses the eating out trade
If the Pfizer/BioNTech and Moderna vaccines pass their remaining regulatory tests and are followed by others as immunologists expect, there could be a substantial vaccination programme under way early in the new year. This will fight off the virus should those vaccinated be infected, and there is optimism that they could also be unable to infect others. If sufficient numbers take a vaccine which protects a high percentage of those who take it, the population can reach herd immunity, where the epidemic begins to die out for want of sufficient people remaining susceptible to infection.
Most of those who catch COVID-19 recover and cease to be infective after some weeks, or a few months in more serious cases.
These first vaccine announcements are milestones and there will be further results in the weeks ahead
They become immune, although there have been some rare incidents of reinfection. This, plus immunisation through vaccines, could bring the pandemic phase to a close in the year 2021, even if the disease is not completely eradicated.
These first vaccine announcements are milestones and there will be further results in the weeks ahead.
Whether the uptake of approved vaccines delivers enough immunity in the population depends on four factors:
The percentage of vaccine recipients who are protected. For the Pfizer/BioNTech discovery, the preliminary figure is 90%, for Moderna 94.5%. The percentage of the population who take the vaccine.Any additional percentage who have become immune after recovery from infection. The percentage threshold for herd immunity.Most experts believe that the disease will begin to die out once 60% or 70% of the population have attained immunity, either through taking a vaccine or through infection and recovery. But it depends on behaviour – if people observe strict social distancing indefinitely, herd immunity would be attainable at a lower threshold.
If there were no public health policy at all, the let-it-rip approach with no vaccine, herd immunity could require a threshold of 90% or even higher, after much illness and a horrendous toll of deaths.
If vaccination proves to be 90% effective, better than the pre-trial expectations, this would be great news. With, say, 70% of the population opting for vaccination, 63% (0.9 times 0.7) would become immune and hopefully non-infectious. Add another 2% or 3% for immunity from the infected-but-recovered group and you get right into the range where herd immunity (plus some continuing careful behaviour) would be sufficient to end the epidemic.
How many people in Ireland would take the vaccine, assuming it would be entirely voluntary? The polling company IPSOS/MRBI reported these figures recently, before the good news from Pfizer/BioNTech was released (Figure 1).
Pessimistic
Some of the news media reported the story along the lines of “only 55% will take vaccine” but this seems too pessimistic. If half of the “not sures” decide to do so, just over 70% would oblige and immunity could be high enough to stop the epidemic.
Sentiment could also tilt towards compliance as the positive vaccine stories emerge in the coming months.
Some employers, for example in the health sector and in public transport, could require employees to vaccinate and the public could exhibit a preference for retail outlets able to advertise “all staff have been vaccinated”. The anti-vax lobby groups include some conspiracy theorists who can expect a rough ride in the media but there are also people with understandable concerns about any new vaccine.
The Government and the pharmaceutical industry will need to engage transparently with this group and to listen to genuine concerns. The nature and scale of the safety trials currently under way needs to be explained.
It is now clear that the failure to institute proper testing at airports and seaports has been a weakness in the Irish response to COVID-19.
During the summer, Nphet ascribed very few cases to the category “travel” even though there is definitive evidence that a strain of the virus uniquely traceable to Spain showed up around northern Europe, including Ireland, courtesy of returning holidaymakers.
The public health experts have changed their tune about travel
Propagation from this source was instead identified as “community transmission”, Nphet-speak for “we do not know”.
The public health experts have changed their tune about travel and have expressed the fear that travel over Christmas, especially from high-incidence countries such as the United Kingdom, could undo whatever is achieved through the second lockdown.
Relaxing lockdown for Christmas will be easy. The risk is that it will return
Testing systems were introduced at several European airports as long ago as June and the complacency of Nphet about travel during the summer may help to explain the Irish delay.
International airlines and travel industry lobby groups insist that rapid antigen tests, even if they give some false negatives, are preferable to the slower, and more expensive, PCR tests of which Irish health officials appear curiously enamoured.
Relaxing lockdown for Christmas will be easy. The risk is that it will return for Valentine’s Day before vaccination gets going.
Read more
COVID-19 transforms food consumption
COVID-19 collapses the eating out trade
This is a subscriber-only article
SHARING OPTIONS: