Covid-19 vaccination drive
WHO advice on third dose
Commending Sri Lanka’s vaccination drive, Dr. Alaka Singh, WHO Representative to Sri Lanka said, “it has been successful both in terms of coverage as well as preventing severe disease and hospitalisation”.
Considering only the eligible population, she said that Sri Lanka has vaccinated over 85 percent, administering more than 14 million doses. “This is a remarkable achievement,” she said. Dr. Singh also acknowledged that this was made possible “by the sound primary healthcare foundation in Sri Lanka with its strong routine immunisation program. This formed the basis of the vaccine drive, facilitated by a whole of Government and whole of society approach,” she added.
The WHO also issued its first announcement regarding the third dose of Covid vaccines. It advised that ‘moderately and severely immune compromised persons should be offered an additional dose of all WHO EUL Covid-19 vaccines as part of an extended primary series’.
Dr. Singh, who assumed responsibilities as the WHO Representative to Sri Lanka in May this year, responded to more questions on Covid control measures, especially as schools in Sri Lanka reopened last week. Following are excerpts of the interview.
Q: What is your view of Sri Lanka’s vaccination drive so far?
A: Sri Lanka’s vaccination drive has spearheaded the country’s Covid-19 response and has been successful both in terms of coverage as well as preventing severe disease and hospitalisation. WHO’s call is for countries to fully vaccinate 40 percent of their population by the end of the year. Sri Lanka has already achieved 58 percent full coverage with increased eligibility to include school students 16 years and above as well as children 12 years and older with comorbidities. In fact, if we consider only the eligible population, Sri Lanka has vaccinated over 85 percent which means administering more than 14 million doses. This is a remarkable achievement.
It is important to note here that this was made possible by the sound primary healthcare foundation in Sri Lanka with its strong routine immunisation program. This formed the basis of the vaccine drive, facilitated by a whole of Government and whole of society approach.
Q: What are WHO’s recommendations on an additional dose of vaccine?
A: We need to be precise here. Earlier this month, the global Strategic Advisory Group of Experts (SAGE) has recommended as follows on an additional third dose:
Moderately and severely immune compromised persons should be offered an additional dose of all WHO EUL Covid-19 vaccines as part of an extended primary series. This is advised because these individuals are less likely to respond adequately to vaccination following a standard primary vaccine series of two doses as administered in Sri Lanka and are at higher risk of severe Covid-19 disease.
For the Sinovac and Sinopharm inactivated vaccines, an additional (third) dose of vaccine from the same vaccine type should be offered to persons aged 60 and above as part of an extended primary series. The use of other vaccine types or ‘mixing and matching’ these vaccines – for example, with a Pfizer for the additional dose may also be considered based on vaccine supply and access considerations. When implementing this recommendation, countries should initially aim at maximising 2-dose coverage in that population, and thereafter administer the third dose, starting in the oldest age groups.
We need to be precise because a 3rd additional dose as a part of the primary series is different from booster doses.
Q: Then what is the difference between a third dose and a booster?
A: The third dose is an additional dose given as an extension of the primary series for those whose immune systems are compromised and cannot generate an adequate level of immunity to protect from severe disease and hospitalisation even after two doses. Sri Lanka is moving forward on a third dose for the at-risk population group of over 60 from next month.
Boosters are given when the protective effect of the vaccine is waning. SAGE is still reviewing the evidence for boosters for each of the WHO recommended vaccines and shall issue advice accordingly early next month.
Q: Can vaccination prevent long Covid?
A: Most people with Covid-19 are asymptomatic, experience mild symptoms or moderate illness, approximately 10-15 percent of cases progress to severe disease, and about five percent become critically ill. Typically, people recover from Covid-19 after two to six weeks and return to normal health.
However, some can have symptoms that last for weeks or even months after recovery though they are not infectious to others during this time. Even people who were not hospitalised and who had mild illness can experience persistent or late symptoms and some patients develop medical complications that may have lasting health effects. This persistent state of ill health is known as ‘post Covid condition’.
The best way to prevent post-Covid conditions is to prevent Covid-19 illness itself. The vaccines currently available prevent severe disease and death with some protection against infection especially when combined with public health and social measures. And, there is emerging evidence that suggests the same for long Covid-19: those who develop Covid-19 while being fully vaccinated are less likely to have symptoms for more than a month.
Q: Against the background of the vaccination effort in Sri Lanka, what are your views on schools reopening?
A: WHO has developed detailed guidance on health-related issues for countries considering reopening of schools, as Sri Lanka is doing. Studies indicate that children are less affected by Covid-19 infection and, also, that the severity of infection is lower.
Children make up eight percent of Covid-19 cases globally while they constitute 30 percent of the population. Within the age group, infection occurs more often in teenagers rather than in younger children. Overall, school prevalence reflects the background of transmission in the communities they operate.
Two facts are relevant here for Sri Lanka: first, the high vaccination coverage that includes over 95 percent of all school staff; and, the clear transition to lower transmission levels and a significant decline in cases and deaths in the past weeks.
Restarting schools may be considered with adequate safety and surveillance measures using appropriate strategies e.g. staggered opening, with primary sections first; or, using hybrid learning.
WHO emphasises the critical importance of safe opening with comprehensive public and social measures, with special attention to those at risk.
Implementing this requires a multi-layered approach anchored in the local context and involving school staff, parents, children and the community.
Further, overall planning and monitoring needs to be in place in a way that is consistent and reinforcing across levels – national, district and schools.