Challenge for COVID-19 vaccines to protect the New Zealand population
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EDITORIAL
Challenge for COVID-19
vaccines to protect the
New Zealand population
Stephen T Chambers, Nigel J Raymond
N
ew Zealand faces a major challenge vaccine, the relatively good effectiveness
this year to use the COVID-19 (SARS- of influenza vaccine and the current
CoV2 virus) vaccination programme public acceptance of social distancing
to optimise protective immunity, in order and improved personal hygiene. No one
protect our largely non-immune population. strategy alone will deliver all of the health
The practical goal is to achieve a high uptake benefits we need. The health professional
of vaccination while not leaving any parts of community and the public both have
the community unprotected. Never before important roles if our country is to make the
has the country had such a programme of most of this opportunity.
vaccinating so many people within such a
short time frame. COVID-19 vaccine response
This challenge in made more acute as New Zealand is well placed to roll out the
the New Zealand health system has a long COVID-19 vaccination programme as there
and challenging experience of responding are purchase agreements for sufficient Pfizer
to seasonal winter increases in respiratory vaccine (PfizerBioNTech) to give two doses to
viruses, particularly influenza. The uptake the population. This is a mRNA-based vaccine
of publicly funded influenza vaccine has that stimulates cells to make spike protein
remained modest, with ongoing equity gaps antigen, but does not incorporate itself into
for important high-needs populations (eg, human DNA.2,3 The vaccine vials require an
Māori) despite the well-publicised effects on ultra-cold chain for transportation to New
the health system. The immunisation rate Zealand where they are held in -80°C freezers.
for influenza was reported as 63% overall These facilities are already in place across
for 2019 despite ongoing improvement the country. The vaccine can then be stored
from previous years and some reductions at 2–8°C for up to five days after thawing for
in equity gaps.1 These infections routinely distribution to use at vaccine administration
cause unseemly bed shortages and compro- sites around the country. Use of standard
mised delivery of healthcare services across pharmaceutical freezer temperatures (-20°C)
the country. At present we do not know what for up to two weeks, recently approved in
shape future possible winter outbreaks of New Zealand by MedSafe, should consid-
COVID-19 infections will take, but COVID-19 erably aid distribution.4 Vials have sufficient
added to the normal pattern of winter viral content for 5–6 doses and must be used
infections creates a daunting prospect. The within a few hours of opening. The second
combination of a winter increase in influenza dose should then be administered at least
cases plus COVID-19 cases in similar numbers three weeks (or longer) after the first dose.
would undoubtedly lead to a substantial The Pfizer vaccine has been found to be
increase morbidity and mortality from these both highly efficacious in adults of all ages
infections, because of the overall burden and children as young as 12 years from
on the health system and the severity of evidence of large clinical trials, and highly
COVID-19 infections. effective in subsequent large-population
We now have tools to mitigate the experience.2,5 The vaccine has been found
epidemic curve of both COVID-19 and to be highly immunogenic and produces
influenza, as well as other viral infections, higher levels of neutralising antibodies than
given the effectiveness of the COVID-19 following wild-type COVID-19 infection,
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even in older adults (55–85 years). The for excellent efficacy and safety of the Pfizer
most important phase 3 clinical trial was vaccine in subjects aged 12–16 years.5 This
conducted across multiple sites in the is welcome news. While children are less
United States, Argentina, Brazil, South prone to both asymptomatic and symp-
Africa, Germany and Turkey.2 The study tomatic COVID-19 infections and play a lesser
enrolled 43,448 people and was conducted role in transmission within families to more
in accordance with rigorous FDA standards. vulnerable members, there has been of
Failure was defined as being symptomatic lingering concern that this could provide an
and having laboratory confirmed COVID-19 under-recognised pathway for transmission.
seven days after the second dose was As yet there is little information on how
administered. In those with no evidence of long protection is likely to last and how
prior infection the vaccine efficacy was 95% effective the Pfizer vaccine will be against
(95% CI 90–98%). Vaccine efficacy among COVID-19 variants. Studies using a rapid
subgroups (age, sex, race, ethnicity, obesity neutralising antibody assay of serum taken
and comorbidities) was consistent with from patients who have had a natural
that observed in the overall population. infection or two doses of the Pfizer vaccine
There are limited published studies as yet found that the faster spreading COVID-19
on the effectiveness in the ‘real world’, but variants acquired a partial resistance to
reports we have so far show impressive the neutralising antibody.11 This was most
results in preventing hospitalisation and marked for the B1.351 variant, suggesting
death. For example, Public Health England that the vaccine may be less effective against
has reported that a single dose of either the this organism. The poorly controlled spread
Pfizer or AtraZeneca vaccines cut the risk of of COVID-19 in large populations in Europe,
hospital admission by 80% in people over South America and South Asia is almost
80 years.6 In Israel, two doses of the Pfizer certain to allow more variants to emerge.
vaccine administered to a cohort of 596,681 In addition, piecemeal or poorly rolled out
people reduced hospitalisations by 87% (95% vaccination programmes are likely to create
CI 55–100) and severe disease by 95% (95% further evolutionary pressure towards the
CI 75–100) compared with unvaccinated selection of escape variants of COVID-19. It
controls.7 Experience in Scotland found a is likely that booster vaccines will be needed
vaccine efficacy of 85% (95% CI 76–91) for with new antigens added to the suite of
COVID-19 related hospitalisation at 28–34 vaccines against COVID-19 over time.12
days post vaccination.7 More recently, a
study showed a similarly high vaccine Community immunity
efficacy in children age 12–16 years.5 The implementation of the public health
A growing body of evidence also demon- measures in New Zealand to ‘suppress the
strates that fully vaccinated people are less curve’ during the first half of 2020 was
likely to have asymptomatic infection and remarkably effective and showed that
potentially much less likely to transmit elimination was possible. Most vaccination
SARS-CoV-2.8 The few cases of infection programmes aim at disease reduction to
following vaccination that have been some ‘tolerable’ level, and it remains to be
reported are associated with a shorter mean seen whether prevention of endemic trans-
duration of symptoms and often lower viral mission by ‘herd protection’ is possible.5,13–16
load than infection in unvaccinated people.9 Both elimination and control strategies aim
For example, a study of 3,950 front-line at protecting the maximum number of indi-
health workers, most of whom had been viduals at risk. Following completion of the
vaccinated with either the Pfizer and current vaccination programme, is seems
Moderna vaccine (another RNA vaccine), unlikely that we will be going straight back
found a 90% reduction of symptomatic to ‘normal’, and we may need to navigate a
and asymptomatic infections following the pathway to a hopefully low level of endemic
second vaccine dose.10 infection. It is doubtful that aiming for an
There are clearly areas of uncertainty arbitrary target, such as 70% of the adult
that need to be clarified. These include the population being vaccinated, would be suffi-
effectiveness of the vaccine in children. cient to control COVID-19, as the degree of
There is good evidence from a recent study asymptomatic spread reduction is still not
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established and immunity is rarely uniform Individuals who have been affected,
across a population. So we will need to or whose families/whānau have been
ensure subpopulations are adequately affected, by COVID-19 have an important
protected. To do this we need to specifically role to play in advocating for an effective
address some challenging factors. whole of community approach. This could
Firstly, it is essential that all sections of include managed isolation and quarantine
society are reached with vaccination, espe- (MIQ) staff who have been vaccinated and
cially those with comorbidities, including presumably feel a significant measure of
Māori and Pacific Island communities, reassurance from the protection this offers,
advanced age (eg, rest-homes), and particu- healthy people who have been affected
larly if their community may be more likely by suffering a serious COVID-19 illness, or
to be exposed (eg, South Auckland). It will be those who have been affected by the ‘long
a huge operational challenge to reach most COVID syndrome’ that compromises their
of New Zealand’s population with COVID-19 enjoyment of life in the long term.
vaccination during the year. The national
COVID-19 immunisation register is a vital Benefits of an effective vaccination
component of this strategy and will be programme
needed for future vaccines delivery. The vaccination programme has
Secondly there has been a major effort important implications. Many people will
launched to overcome vaccine hesitancy. be keen to break out from the restrictions
It is imperative that healthcare profes- of the infection prevention and control
sionals take responsibility to provide (IPC) measures, such as social distancing
independent, high-quality and clear infor- and use of masks on public transport. These
mation to address legitimate concerns and measures have undoubtedly been effective
counter misinformation. Health staff should in reducing the rate of transmission of
be well informed so that the vaccination COVID-19 and also influenza and other
programme can be discussed during hospital severe respiratory infections. The benefits
admission and outpatient clinics, as well as of these measures should be pursued in the
general practitioner visits. The importance short term until there is a reliably high level
of taking into account behavioural and of community immunity from COVID-19,
social drivers of vaccine uptake, including and then they should be seen as part of the
during healthcare interactions, has also normal response to the annual winter respi-
been emphasized by the World Health ratory virus epidemics.19
Organisation (WHO) in their BeSD model New Zealand has opened a ‘bubble’ with
in endeavouring to achieve high uptake of Australia, and other countries will soon be
COVID-19 vaccines (Figure 1).17,18 added to this. But there will be an ongoing
Figure 1: The BeSD of Covid-19 model.
Source: Based on the “increasing vaccination” model (Brewer et al., 2017).18
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need for the MIQ border protections. These vector) does not seem to be a problem with
have worked well and limited community the Pfizer vaccine. The specific clotting
incursions to outbreaks, which have been problems have produced very serious, if
contained by intensive work by Public rare, clinical effects, including cavernous
Health Units (PHUs). Extensive vaccination sinus thrombosis and deaths, which are
of the staff manning these facilities will likely to be clinically recognised within
offer a further layer of protection against OECD medical systems. Given the intense
an importation, and high uptake of vacci- scrutiny engendered by the publicity of
nation in communities who later become clotting problems with the other vaccines, it
contacts of an infected traveller would seems very unlikely that these problems are
greatly help this situation by lowering the associated with the Pfizer vaccine. Moni-
effective transmission reproductive number toring of the primary outcomes from the
(Ro) and limiting community spread to be trials will continue until August 2021, while
containable. This would greatly lower the monitoring of the secondary outcomes will
burden on PHU to contact trace and shut continue until January 2023.22
down outbreaks and minimise the need for
lockdowns. Leadership from healthcare
providers
Vaccine safety evidence and New Zealand owes a great debt of grat-
monitoring (high) itude to the leadership provided by the
A comprehensive discussion of vaccine government and health leaders who have
safety is beyond the scope of this paper. communicated so effectively with the public.
However, the evidence from controlled The next hurdle is to roll out the vaccine
trials has found that the Pfizer vaccine is in a coordinated and equitable way. There
extremely safe.10,20 The most common side are already several effective vehicles for
effects include mild to moderate pain at providing information on the ongoing
the injection site in about 80% of subjects, evolution and response to the COVID-19
fatigue in about 60% and headache in epidemic. It is important that healthcare
about 50% of subjects.21 All were short providers support the strategy by helping
lived. Reports of serious side effects, such to build confidence in the outcomes as we
as allergic reactions, have been very rare, mediate between the overall policy and the
and no long-term complications have been concerns of our patients. Key ingredients
confirmed. The clotting problems with that needed in this roll-out are clarity of purpose,
have been associated with the Oxford Astra- knowledge of the benefits and safety of the
Zeneca and possibly with Johnson & Johnson vaccine and optimism that a scientific and
vaccines (both of which use an adenovirus humane response will be effective.
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Competing interests:
Nil.
Acknowledgements:
The authors thank Dr Nikki Turner and Prof David Murdoch,
for reviewing and comments on the manuscript.
Author information:
Nigel J Raymond: Infectious Diseases & General Physician,
Infection Service, Capital & Coast District Health Board;
Department of Medicine, University of Otago, Wellington (Honorary CSL).
Stephen T Chambers: Department of Pathology, University of Otago,
Christchurch. Infectious Diseases Physician Christchurch Hospital.
Corresponding author:
Dr NJ Raymond, Infection Service, Lv6 GNB, Wellington Hospital,
Private Bag, Wellington, +64-4-385-5999
nigel.raymond@ccdhb.org.nz
URL:
www.nzma.org.nz/journal-articles/challenge-for-covid-19-vaccines-to-protect-the-new-zea-
land-population-open-access
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