Pilot Study on Evaluating the Impact of Tetanus, Diphtheria, and Pertussis (Tdap), Influenza, and COVID-19 Vaccinations on Antibody Responses in Pregnant Women

Abstract

This study assessed IgG levels to influenza/pertussis and neutralizing antibody (Nab) responses of COVID-19 vaccines in blood of pregnant women following immunization with pertussis (Tdap), influenza, and COVID-19 vaccines. We prospectively collected 71 participants categorized by the following vaccine combinations: 3TI, 4TI, 3T, and 4T groups (three and four doses of COVID-19 vaccines plus Tdap/influenza or Tdap vaccines alone). Our findings have indicated that the 3TI group exhibited elevated IgG levels for influenza B compared to the 3T group (12.90 vs. 7.75 U, p = 0.001); this pattern was not observed for influenza A. Pertussis IgG levels remained uniform across all groups. The 4TI group demonstrated a greater Nab inhibition rate from COVID-19 vaccines compared to both the 3TI and 3T groups (61.34% vs. 22.5% and 15.16%, respectively, p = 0.001). We observed no correlation between Nab inhibition rate and IgG levels for Tdap/influenza, with the exception of a moderate correlation with influenza B in the 3TI group. The efficacy of Tdap vaccine in pregnant women remained consistent, regardless of the administration of COVID-19 or influenza vaccines. Interestingly, without the influenza vaccine, both three and four doses of the COVID-19 vaccine still offered protection against influenza A, but not B. Hence, co-administering COVID-19, influenza, and Tdap vaccines during prenatal care maintains immunogenicity and is highly advised to safeguard pregnant women fully.

Keywords: COVID-19 vaccine; Nab; Tdap; influenza; maternal vaccination; neutralizing antibody; pertussis; pregnancy.

Figure 1

IgG levels for influenza A and B among participants vaccinated with three or four doses of the COVID-19 vaccine: impact of pertussis/influenza versus pertussis-only vaccination. ****, p < 0.0001.

Figure 2

Comparison of IgG antibody to influenza A/B and pertussis for participants that received 3 doses and 4 doses of COVID-19 vaccine and Tdap and influenza vaccine. Tdap, the tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis.

Figure 3

Comparison of IgG antibody to influenza A/B and pertussis for participants that received 3 doses and 4 doses of COVID-19 vaccine and Tdap vaccine alone. Tdap, the tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis.

Figure 4

Comparison of IgG antibody to pertussis for participants receiving 3 or 4 doses of COVID-19 vaccine with or without antenatal influenza vaccination.

Figure 5

Correlation among Nab inhibition rates to Omicron BA.5 SARS-CoV-2 and IgG antibody to influenza A/B and pertussis in participants that received 3 doses of COVID-19 vaccine and Tdap/influenza or Tdap alone vaccination. 3TI group, 3 doses of COVID-19 vaccines plus Tdap/influenza vaccines; 3T group, 3 doses of COVID-19 vaccines plus Tdap vaccine; Nab, neutralizing antibody; Tdap, the tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis; *, p < 0.05.

Figure 6

Correlation among Nab inhibition rates to Omicron BA.5 SARS-CoV-2 and IgG antibody to influenza A/B and pertussis in participants that received 4 doses of COVID-19 vaccine and Tdap/influenza vaccination. 4TI group, 4 doses of COVID-19 vaccines plus Tdap/influenza vaccines; Nab, neutralizing antibody; Tdap, the tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis.