Published: 19 July 2023

COVID-19

Post Vaccine Symptom Check: Bivalent COVID-19 vaccine survey results

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Medsafe advises people NOT to make any decisions about vaccination based on information contained in this report. If you have questions or concerns about receiving a vaccine, please speak to a health care professional.

• Introduction
• About the PVSC surveys
• Survey results

Introduction

The information from the Post Vaccine Symptom Check (PVSC) survey supports ongoing safety monitoring of Comirnaty, the Pfizer COVID-19 vaccine used in Aotearoa New Zealand. Find out more about how we are monitoring COVID-19 vaccine safety.

The data collected from the PVSC survey has not raised any new safety concerns for the Pfizer COVID-19 bivalent vaccine.

About the bivalent PVSC survey

On 1 March 2023, the Pfizer bivalent COVID-19 vaccine replaced the existing Pfizer vaccine used for booster doses. The bivalent vaccine contains two strains of the COVID-19 virus, including an Omicron strain.

The bivalent COVID-19 vaccine PVSC campaign began on 1 April 2023. Te Whatu Ora sent text messages to a random sample of people who had received the bivalent vaccine. The text messages asked people they had experienced an adverse event/reaction after their vaccination, and if they would like to participate in the survey. Participants completed a day 7 and day 42 survey to provide more information about the adverse event.

The information on this page shows the number of responses from a randomly sampled population as part of the PVSC campaign. It does not represent the total number of people who were vaccinated nor the total number of people who experienced an adverse event after their vaccination. Not everyone will report a reaction to the vaccine through the PVSC campaign, and some might submit a report to the Centre for Adverse Reactions Monitoring (CARM).

The number of vaccine adverse event reports in a PVSC campaign can be influenced by the number of participants, the nature of the symptoms (eg, how painful the vaccination was), and other factors (eg, concurrent viral infection or other medicines taken), which vary over time.

The information presented below is limited to responses to the survey for bivalent COVID-19 vaccinations in those aged 18 years and older. Data collected from the bivalent PVSC campaign is also in line with data collected from clinical trials and from post-marketing surveillance in New Zealand and overseas. Based on this data, we have not identified any new safety concerns for the Pfizer bivalent COVID-19 vaccine.

Survey results – up to and including 5 June 2023

From 1 April through 5 June 2023, there were 191,504 text messages sent to eligible people. Of these, 128,216 ‘Yes’ and ‘No’ responses were received (Table 1).

Of those who responded to the survey:

• 57% were female, and 43% were male, less than 1% were unknown, and less than 1% were gender diverse
• 11% of respondents were Māori, and 3% were Pacific peoples.

Of the responses received (Table 2):

• 23% reported that they experienced at least one adverse event/reaction to the vaccine
• 77% reported that they did not experience an adverse event.

The proportion of people who reported an adverse event was similar for each ethnicity (Figure 1).

The most frequently reported adverse events were injection site reactions, fatigue or tiredness, headache, muscle aches or pain, flu symptoms, chills and dizziness or light headedness (Figure 2). These are common adverse reactions linked to the immune response following immunisation.

Four percent of people who participated in the bivalent COVID-19 vaccine PVSC campaign reported missing work or other daily activities. Of these, the majority were reported to have missed one day or less. Less than one percent (0.4%) of people visited a doctor after vaccination (Figure 3).

The profile of reported events to PVSC for the Pfizer bivalent COVID-19 vaccine is similar to that reported for the dose 1, 2 and booster PVSC campaigns.

Table 1: Summary of text message responses, 1 April through to 5 June 2023

Campaign	Number of people sent text messages	Number of responses received	Percentage of responses received
Bivalent COVID-19 vaccine	191,504	128,216	67%

Table 2: Responses by vaccine dose and adverse event, 1 April through to 5 June 2023

Dose	Did not report an adverse event		Reported at least one adverse event
	Number	%	Number	%
Bivalent COVID-19 vaccine	98,976	77%	29,149	23%

Figure 1: Percentage^a of people that reported an adverse event following the bivalent COVID-19 vaccine, by ethnicity, 1 April through to 5 June 2023

Note:

1. Percentage for each dose number and ethnicity group is calculated based on the number of people that responded in those groups.

Figure 2: Most frequently reported^a following bivalent COVID-19 vaccine, percentage^b by dose, 1 April through to 5 June 2023

Notes:

1. PVSC survey answers may come from one person, but that person may report more than one adverse event. As with any adverse event reports, not all symptoms reported may be caused by the vaccine; they may be coincidental and due to other causes.
2. For the percentage calculations, the numerator is the number of times the reaction was reported by dose, and the denominator is the total number of participants from which responses were received for the bivalent COVID-19 vaccine.
3. Adverse events reflect wording of survey questions presented to participants, this may differ from other PVSC campaigns, as survey question wording is subject to change.

Figure 3: People that visited a doctor^a after vaccination with the bivalent COVID-19 vaccine, 1 April through to 5 June 2023

Note:

1. The PVSC survey does not specifically ask for the reason why the person accessed medical care in the days following vaccination. Therefore, medical attendance reported may or may not be related to any adverse events reported.