England's deputy chief medical officer Jonathan Van-Tam warned that vaccinated people could still transmit the Covid-19 virus.
In an article on the Sunday Telegraph, Professor Van-Tam pointed out that scientists "do not yet know the impact of the vaccine on transmission" so vaccinated people may still spread the Covid-19 virus so they should continue following lockdown rules.
He argued that while vaccines offer "hope", infection rates must come down quickly. Van-Tam added that "no vaccine has ever been" 100% effective, so there is no guaranteed protection.
Possibility of transmission
Prof. Van-Tam said there is a possibility of contracting the virus in the two- to three-week period after receiving a vaccine and that it is "better" to allow "at least three weeks" for an immune response to fully develop in older people.
"Even after you have had both doses of the vaccine you may still give Covid-19 to someone else and the chains of transmission will then continue," he said.
The deputy chief medical officer continued: "If you change your behavior you could still be spreading the virus, keeping the number of cases high and putting others at risk who also need their vaccine but are further down the queue."
Senior doctors from the British Medical Association (BMA) have called on England health officials to reduce the gap between first and second doses of the Pfizer-BioNTech vaccine. Currently, the maximum waiting period between two doses has been extended from three weeks to 12 weeks in order to roll out first doses to more people in the UK.
The doctors argued that the policy was "difficult to justify" and the gap should be shortened to six weeks. BMA chairman Dr. Chaand Nagpaul pointed out that there were "growing concerns" that the vaccine could potentially be less effective with doses 12 weeks apart.
However, Van-Tum responded: "What none of these (who ask reasonable questions) will tell me is: who on the at-risk list should suffer slower access to their first dose so that someone else who's already had one dose (and therefore most of the protection) can get a second?"
UK variant more lethal?
Prime Minister Boris Johnson says the new Covid-19 variant first detected in the UK may be deadlier than previous strains.
Speaking about the new UK variant at a news conference, Prime Minister Johnson said: “We’ve been informed that in addition to spreading more quickly… there is some evidence that the new variant… may be more associated with a higher degree of mortality.”
However, he added: “Both the vaccines we’re currently using remain effective both against the old variant and this new variant.”
UK’s chief scientific adviser Patrick Vallance mentioned that patients who were hospitalized with the new variant did not appear to have a higher risk of dying in comparison to patients hospitalized with the original form of the virus.
“However, when data are looked at in terms of… anyone who has tested positive there is evidence that there is an increased risk for those who have the new variant compared to the old [one,]” Vallance explained.
But he pointed out that the evidence is weak and the data needs more certainty.
