Pregnancy alters respiratory physiology and immunity, increasing susceptibility to complications from acute viral infections. Influenza and COVID-19 remain the two respiratory pathogens most likely to lead to maternal hospitalisation, intensive care, and adverse perinatal outcomes.^1,2 General practitioners are pivotal in prevention (vaccination), early diagnosis, timely antiviral therapy, and coordinated follow-up across antenatal and postpartum care.

Haemodynamic changes (increased oxygen consumption, decreased functional residual capacity), mucosal oedema, and pregnancy-related immunomodulation together raise the risk of severe viral disease. Both influenza and SARS-CoV-2 infections in pregnancy are associated with higher odds of hospitalisation and ICU admission than in non-pregnant peers, and COVID-19 has been linked to increased risks of preterm birth and other adverse outcomes.³ Postpartum women (up to two weeks) also remain at elevated risk for influenza complications as cardiopulmonary physiology normalises.

Vaccination: The Strongest Protection

Influenza

An inactivated or recombinant influenza vaccine is recommended in every pregnancy, in any trimester, as soon as seasonal vaccine becomes available.¹ Vaccination reduces maternal influenza, hospitalisation, and febrile illness, and provides passive protection to infants via transplacental transfer of IgG – important because babies cannot be vaccinated until six months of age.⁴

Co-administration with other non-live vaccines (e.g. Tdap, maternal RSV, COVID-19) is safe and effective,⁵ and opportunistic same-day delivery should be used to lift coverage. Australian guidance (ATAGI/NCIRS) aligns with these principles and supports co-administration during pregnancy and revaccination in the same pregnancy if seasons span calendar years.⁶

COVID-19

Major professional bodies continue to advise vaccination during pregnancy and lactation to prevent severe COVID-19 and adverse pregnancy outcomes, and to confer passive infant protection.^7,8 Local product availability and eligibility criteria vary over time; clinicians should follow national schedules and ACOG/WHO updates for vaccine product selection and booster timing. Co-administration with influenza vaccine is acceptable.⁹

Counselling is important for compliance. Emphasise maternal benefits (preventing severe disease) and neonatal benefits (antibody transfer), reassure about non-live vaccine safety, and invite questions about timing. For patients with vaccine hesitancy, brief, strong, and presumptive recommendations from the primary clinician consistently improve uptake.⁹

Recognising and Testing

Clinical presentations of influenza and COVID are often similar. During the respiratory-virus season, test for both influenza and SARS-CoV-2 when compatible symptoms are present, especially in the third trimester or in patients with comorbidities.³

Treat Early: Antivirals Save Lives

Influenza Antivirals

Start oseltamivir 75mg orally twice daily for five days as soon as influenza is suspected – do not await test confirmation, and do not withhold treatment because symptom onset exceeds 48 hours if the patient is severely ill or deteriorating.¹⁰ Pregnancy is not a contraindication to neuraminidase inhibitors; oseltamivir remains the preferred agent because of oral dosing and the most robust pregnancy safety data.¹⁰ Zanamivir (inhaled) or peramivir (IV) are alternatives when oseltamivir is not feasible. Baloxavir is not recommended in pregnancy due to insufficient data.¹¹

Treat fever promptly – paracetamol is appropriate and safe in pregnancy; avoid routine NSAIDs after 20 weeks’ gestation because of risk of oligohydramnios and fetal renal impairment.¹²

Offer post-exposure prophylaxis (e.g., oseltamivir 75 mg daily for seven to ten days) to pregnant or early postpartum close contacts at high risk after confirmed exposure, alongside vaccination where not yet given.¹⁰

COVID-19 Therapeutics

For non-hospitalised pregnant patients at risk of progression, nirmatrelvir–ritonavir (Paxlovid) is first-line within five days of symptom onset,^13,14 provided drug–drug interactions are assessed; major professional guidance advises not withholding this therapy on the basis of pregnancy or lactation alone.

Remdesivir (three-day IV regimen for outpatients; longer courses for inpatients with hypoxaemia) is a reasonable alternative when Paxlovid is unsuitable;¹⁵ growing pharmacokinetic and observational data suggest acceptable safety in pregnancy, though high-quality efficacy data are limited.¹⁵ Molnupiravir should be avoided in pregnancy because of potential fetal toxicity; consider only if no other options are available and after shared decision-making.³

Manage hypoxaemia aggressively; consult obstetric and infectious diseases colleagues early for hospitalised patients.³

Summary

The evidence base for influenza management spans many seasons and consistently supports maternal vaccination and early neuraminidase inhibitor therapy in pregnancy. For COVID-19, multiple observational data sets and living guidelines demonstrate higher maternal morbidity and preterm birth with infection,¹⁶ and support vaccination and time-sensitive outpatient antiviral therapy in pregnancy.

Data for remdesivir in pregnancy are increasingly supportive but still limited; when indicated for hospitalised cases, decisions should be individualised with multidisciplinary input. Guidance on vaccine schedules evolves with variant epidemiology; check current local and national recommendations.