According to respiratory medicine expert Professor Christine Jenkins, an increased COVID-19 uptake in New South Wales will take about three weeks to make a difference to virus outbreak conditions in the state’s hot spots.
As NSW premier Gladys Berejiklian calls for more people in Greater Sydney to step forward and get their first or second dose of the COVID-19 vaccine, an expert has explained that the positive effects of wide vaccination uptake will take time.
According to Professor Christine Jenkins, the head of the respiratory group at the George Institute for Global Health, after 14 days of receiving a first dose, a person’s risk of virus transmission within their household is reduced. By 21 days, the vaccinated person’s transmission rate in households is reduced by 40-50%.
“Vaccination is likely to reduce the probability of transmitting the infection as early as 14 days. Hence it can reduce our numbers and help shorten the length of the lockdown as well as reduce the probability that we will need further lockdowns,” Jenkins said.
“The sooner a high proportion of the population is vaccinated, the sooner we can return to the freedom we crave.”
Jenkins pointed to a comprehensive study from the UK that analysed the data of over a million vaccinated people compared with unvaccinated people. The study found that for close contacts of someone carrying the virus who was vaccinated 14 days or more before testing positive, their odds of catching the virus from the index case were lower.
“These data suggest that the sooner people are vaccinated, the sooner they are protected themselves and the sooner their close contacts are protected,” Jenkins said.
The view is the same one the NSW government has been trying to hammer home to residents of Greater Sydney concerning the risk they pose to family members when they do not follow public health restrictions or remain unvaccinated.
NSW chief health officer Dr Kerry Chant told a press conference on Friday that people should be calling their older relatives and, with their consent, helping to organise a COVID-19 vaccine booking for them. She said that with more sites to access the AstraZeneca vaccine in the community, it was a ‘no-brainer’ that uptake among older people should improve.
“While the Australian Technical Advisory Group on Immunisation (ATAGI) advice is for anyone over 18 to consider [AstraZeneca], the group that really distresses me […] is we haven’t got high levels of coverage or high enough levels of coverage in the elderly,” Chant said.
“Those elderly people are going to bear the brunt of COVID.”
Chant said she remained concerned about the stubborn number of people in the community over-70 who were not vaccinated. New federal government data released on Thursday showed that only 39% of people over the age of 70 in NSW had received two doses of the COVID-19 vaccines. A total of 77% of NSW residents in this age group have received one dose.
Vaccinations made a ‘dramatic difference’ to reducing the risk of community transmission of COVID-19 and, as Professor Jenkins explained, maximum protection from the virus comes into effect after two to three weeks from a person’s second jab.
“It takes approximately three weeks for a person’s antibody levels to rise to a level that reduces the risk of symptomatic infection with SARS-CoV-2 by about 50% after the first dose, and a further two to three weeks after the second dose to approach the maximum benefit from two doses,” Jenkins said.
ATAGI has provided advice about the timing for the 2nd #AstraZenecaVaccine dose, for people living in areas with an outbreak of the #COVID19 🦠 Delta strain. If you received your 1st dose more than 4 weeks ago, you don’t need to wait 12 weeks. More: https://t.co/lBwMYxU3z3 pic.twitter.com/ksgnrXRgzQ
— Australian Government Department of Health (@healthgovau) July 22, 2021
New advice from ATAGI for people living in Greater Sydney was issued on July 24, urging all adults, including those in the 18-60 age group to consider getting vaccinated against the virus with any available vaccine, including AstraZeneca. The expert panel also recommended that for people living in Sydney’s hotspots to bring forward the time between their two doses from the usual 12 weeks to four to eight weeks.
“The outbreak in NSW continues to grow and the risk of disease, particularly in the greater Sydney area, is likely to continue to be significant over coming weeks,” the expert group said in a statement.
“ATAGI reaffirms our previous advice that in a large outbreak, the benefits of the COVID-19 Vaccine AstraZeneca are greater than the risk of rare side effects for all age groups.”
On Friday the premier announced that Qudos Bank Arena would be administering vaccines to year 12 students in eight areas of concern, who will return to their physical classrooms on August 16. Once about 20,000 senior high school students in the Canterbury-Bankstown, Fairfield, Liverpool, Blacktown, Cumberland, Parramatta, Campbelltown and Georges River LGAs have received their shots, the Qudos Bank Arena will then be used as another mass vaccination hub for the state.
I genuinely reckon this is the sort of social policy decision we should be backing well away from. If it works, fantastic, if it doesn’t, we’ll find out. Anything you see from us medicos on this is pure opinion #auspol #covid19aus #COVID19nsw https://t.co/FWFGm0Xyb7
— Dr. Nick Coatsworth (@nick_coatsworth) July 30, 2021
As part of a revised vaccination strategy to redistribute doses to the areas in NSW most impacted by the COVID-19 Delta strain outbreak, 40,000 doses of the mRNA Pfizer vaccine from a supply that had originally been allocated to the regions will now be given to HSC students in the eight Sydney LGAs of concern.
“GPs continue to supply Pfizer vaccinations in regional NSW, and their supplies from the federal government are unaffected by this reallocation,” a statement from NSW Health said.
“AstraZeneca remains available from GPs, NSW Health clinics and a growing number of pharmacies.”
NSW Health has guaranteed regional communities that people who have already received their first vaccine dose of Pfizer will still receive a second dose. Those people in regional NSW whose booking for a first dose will be impacted by the new vaccine strategy would be contacted as soon as possible, the department added.
Health authorities have also stressed that with the ongoing transmission of the Delta variant in Sydney, the risk of the virus leaking to the regions is something they want to prevent. The strong push for more NSW residents to get vaccinated is needed along with social distancing, mask-wearing and stricter stay-at-home orders, the premier said.
“This Delta strain is contagious, it’s deadly, and it’s affecting people of all ages,” Berejiklian said.
“We also know in NSW that alongside these restrictions, our biggest weapon against the virus is vaccination.”
“Come on Greater Sydney, I’m calling upon everybody to come forward and get vaccinated.”