N.B. COVID-19 roundup: Top doctor defends vaccine mixing after WHO warning causes confusion

New Brunswick's chief medical officer of health is defending the province's approach to mixing COVID-19 vaccines from different manufacturers for first and second doses after a warningfrom the World Health Organization's lead researcher Monday caused confusion.

Dr. Jennifer Russell said the province is following the June 1 recommendations oftheNational Advisory Committee on Immunization (NACI) on the interchangeability of authorized COVID-19 vaccines.

NACI"reviewed all available evidence from ongoing studies monitoring the mixing of COVID-19 vaccines and evidence on the safety of mixing COVID-19 vaccines was available from studies," she said in an emailed statement.

NACI's recommendations say it'ssafe and effective for people to receive an mRNA vaccine either Pfizer-BioNTechor Moderna as a second dose if their first dose was AstraZeneca-Oxford.

For people whose first dose was Pfizer or Moderna,NACI recommends they takeeither of the two products as a second doseif the same first product isn't "readily available" or is unknownbecause they both use a similar mRNA technology.

"No data currently exist on the interchangeability of COVID-19 mRNA vaccines. However, there is no reason to believe that mRNA vaccine series completion with a different authorized mRNA vaccine product will result in any additional safety issues or deficiency in protection," the recommendations state.

The advisory body defines readily availableas "easily available at the time of vaccination without delay or vaccine wastage."

New Brunswick has been mixing first and second doses of AstraZenecaandPfizer, as well as Moderna as it continues to push to reach its goal to have 75 per cent of the eligible population fully vaccinated by Aug. 2.

On Monday, during a global online briefing, WHO's chief scientistDr. Soumya Swaminathan appeared to warnagainst mixing vaccines.

"It's a little bit of a dangerous trend here. We are in a data-free, evidence-free zone as far as mix and match," shesaidas part of a lengthyresponse to a question about the need for booster doses, followingPfizer's announcement that it'sseeking the U.S. Food and Drug Administration's approval to manufacture and distribute third doses.

"There is limited data on mix and match," she said. "There are studies going on.We need to wait for that and maybe it will bea very good approach."

But as it stands, there is only data on using Pfizerafter AstraZeneca, said Swaminathan.

"So it will be a chaotic situation in countries if citizens start, you know, deciding when and who they should be taking a second, or a third or a fourth dose."

She later clarified her remarks in an overnight tweet, saying she warned people against deciding for themselves to mix and match.

"Public health agencies can, based on available data. Data from mix and match studies of different vaccines are awaited immunogenicity and safety both need to be evaluated."

WHO'sstrategic advisory group on vaccines updated its recommendations last monthto say the Pfizer vaccine can be used as a second dose after a first dose of AstraZenecaif a second dose of AstraZeneca vaccine is "not available due to supply constraints or other concerns."

A clinical trial led by the University of Oxfordin the U.K. is also underway to investigatemixing the regimen of AstraZeneca and Pfizer. This trial was recently expanded to include the Moderna and Novovax vaccines, a WHO spokesperson said.

"Vaccine interchangeability is not a new concept," said Russell. "Similar vaccines from different manufacturers are used when vaccine supply or Public Health programs change. Different vaccine products have been used to complete a vaccine series for influenza, hepatitis A, and others."

"Completing your vaccine series by getting a second dose is essential to achieve optimal and longer-lasting protection against COVID-19 disease and associated severe outcomes," she said.

More results from ongoing studies on mixing COVID-19 vaccines are expected in the coming months, according to the Public Health Agency of Canada, including this Canada-wide research study.

Canada has been mixing COVID-19 vaccines for weeks based on emerging research fromSpainand theUnited Kingdomthat found combining AstraZeneca with Pfizer shots was both safe and effective.

"There is a possibility of increased short-term side-effects when mixing COVID-19 vaccines, including headache, fatigue and feeling ill. This was particularly noted with a short interval of [four]weeks between the first and second dose," according to an emailed statement. "These side-effects are temporary and resolve without complications."

No evidence of need for booster

WHO will make recommendations on booster doseswhen it thinks they are needed, saidSwaminathan.

"It may well be that you need boosters after a year or two years, but at this point, after six months after the primary dose, there doesn't seem to be any indication," she said.

Four countries have already announced a booster program and a few more are thinking about it, she said.

If 11 "high and upper-middle income countries" decide to provide a third dose to their populations, or even only to subgroups, an extra 800-million doses will be required,Swaminathan said.

Meanwhile, there are some countries where front-line health-care workers and the elderly, who are most vulnerable, have not been vaccinated, she said.

"At this point there is no scientific evidence to suggest boosters are definitely needed."

WHO's recommendation will be based on science and data, "not on individual companies declaring that their vaccines should now be administered as a booster dose."

0 new cases, 0 in hospital

New Brunswick reported no new cases of COVID-19 on Tuesday for the eighth straight day, and no one in the province is hospitalized with the respiratory disease for the first time in nearly six months.

Fifty-two per cent of New Brunswickersaged 12 and older are also now fully vaccinated, the COVID-19 dashboard shows.

"To achieve our next target of fully vaccinating 75 per cent of eligible New Brunswickers, we need people to continue to roll up their sleeves,"Dr. Jennifer Russell, the province's chief medical officer of health, said in a statement.

"I encourage anyone who hasn't booked an appointment to do so now and help us move closer to our final phase on our path to green."

Once the threshold is reached, the state of emergency mandatory order will end and all Public Health restrictions will be lifted, providedCOVIDhospitalizations remain low and all health regions remain at the yellowCOVIDalert level.

The province's goal is to reach the target by Aug. 2, New Brunswick Day.

Another6,936 second doses of vaccines were administered Monday, meaning 360,545 New Brunswickers aged 12 orolder have received two doses.

The first dose vaccination rate has also inched up again, to 79.7 per cent, with 911 more first doses administered Monday.

Public Health is holding more mobile walk-in Moderna clinics this week to help make getting first and second doses more convenient. Two clinics are underway Tuesday:

• FrederictonMarysville Walk-in Clinic, 231 Canada St.,on Tuesday, between noon and 6 p.m.
• Hillsborough Kiwanis Community Centre, 47 Legion St., onTuesday,between 11 a.m. and 6 p.m.

The other clinics include:

• Perth-Andover River Valley Civic Centre, 11 School St., onThursday, between noon and 6 p.m.
• Dorchester Dorchester Veterans Community Hall, 4955 Main St., on Thursday,between 10 a.m. and 4 p.m.
• Plaster RockTobique Lions Community Centre, 61 Everett Lane., onFriday, between 10:30 a.m. and 4 p.m.
• Salisbury Salisbury Baptist Church, 3128 Main St., on Friday, between 10 a.m. and 4 p.m.

Anyone over the age of 12 is eligible to receive aCOVID-19 vaccine. Theycanbookan appointment onlinethrough a Horizon orVitalithealth network clinic orthrough aparticipating pharmacy.

They are asked to bring their Medicare card, asigned consent form, and for those receiving a second dose, a copy of the record of immunization they received after gettingtheir first dose.

People who booked an appointment but were able to get vaccinated sooner elsewhere are askedto cancel the appointment they no longer need.

4 active cases

New Brunswick has four active cases of COVID-19, Public Health reported Tuesday.

Since Monday, there has been one more recovery and no one is now in hospital.

The last time the province had no hospitalized COVID patients was Jan. 12, said Department of Health spokesperson Bruce Macfarlane.

There have been2,336 confirmed cases of COVID-19 in New Brunswick since the pandemic started, with 2,285 recoveries so far and 46 COVID-related deaths.

A total of 370,042 tests have been conducted, including 878 on Monday.

Atlantic COVID roundup

Nova Scotia reported one newcase of COVID-19 on Tuesday, and has 31 active cases.

Newfoundland and Labrador has no new COVID-19 cases on land, but a second ship is now anchored in Conception Bay with cases on board. The province has 20 active cases, 19 of which involve people on the two ships.

Prince Edward Island has no new cases or active cases.

What to do if you have a symptom

People concerned they might haveCOVID-19 cantake a self-assessment test online.

Public Health says symptoms of the illness have included a fever above 38 C, a new or worsening cough, sore throat, runny nose, headache, a new onset of fatigue, and difficulty breathing.

In children, symptoms have also included purple markings on the fingers and toes.

People with one of those symptoms should stay at home, call CallTele-Care 811 or their doctor, and follow instructions.