tetano
Editor, Senior Moderator
Vet Microbiol
. 2026 Oct 26:323:111273.
doi: 10.1016/j.vetmic.2026.111273. Online ahead of print.
Kasper Pedersen 1 , Patricia Maria Gregersen 2 , Nicolai Rosager Weber 3 , Lars Erik Larsen 4 , Pia Ryt-Hansen 4
Affiliations Expand
The presence of maternally derived antibodies (MDAs) can affect infection dynamics and the immune response in piglets during swine influenza A virus (swIAV) infection. This study aimed to investigate the impact of MDAs on swIAV infection characterized by the duration of swIAV RNA shedding, and serological antibody response in piglets under field conditions. The study was conducted in two Danish sow herds over a six-week period and included five sows with each four piglets in both herds. In addition to unknown previous natural swIAV exposure, sows had been vaccinated with Respiporc FLU3 in Herd 1 one month before study initiation and with Respiporc FLUpan in Herd 2 four months before study initiation. Blood and colostrum samples were collected from the sows on the day of farrowing, whereas nasal swabs and blood samples were collected twice and once weekly, respectively from the piglets. Viral load was estimated by reverse-transcriptase quantitative PCR and swIAV antibody levels in serum and colostrum were assessed by an swIAV-NP ELISA, serum neutralization and hemagglutinin inhibition -tests. Marked variation in antibody levels was observed between herds, sows, and piglets. swIAV RNA was detected in 6/20 piglets in Herd 1 and 17/20 in Herd 2. Due to the twice-weekly sampling interval, exact shedding durations could not be determined. Antibody titers at day 3 were not associated with protection against infection (p > 0.05). However, higher swIAV-NP titers prior to infection were negatively associated with shedding duration in Herd 2 (ρ = -0.67, p < 0.01). Higher swIAV-NP MDA levels were also associated with decreased serological responses after infection (ρ = -0.57, p < 0.05). Overall, MDAs showed limited protection against infection and suppressed adaptive antibody responses in a titer-dependent manner. These findings highlight substantial variability in passive immunity under field conditions and its importance for immune development in piglets.
Keywords: Colostrum; Influenza A virus; Maternally derived antibodies; Pigs; Virus neutralization test.
. 2026 Oct 26:323:111273.
doi: 10.1016/j.vetmic.2026.111273. Online ahead of print.
Maternally derived antibodies impair the development of the adaptive immune response in piglets upon influenza A virus infection and have a limited effect on viral detection
Kasper Pedersen 1 , Patricia Maria Gregersen 2 , Nicolai Rosager Weber 3 , Lars Erik Larsen 4 , Pia Ryt-Hansen 4
Affiliations Expand
- PMID: 42950767
- DOI: 10.1016/j.vetmic.2026.111273
Abstract
The presence of maternally derived antibodies (MDAs) can affect infection dynamics and the immune response in piglets during swine influenza A virus (swIAV) infection. This study aimed to investigate the impact of MDAs on swIAV infection characterized by the duration of swIAV RNA shedding, and serological antibody response in piglets under field conditions. The study was conducted in two Danish sow herds over a six-week period and included five sows with each four piglets in both herds. In addition to unknown previous natural swIAV exposure, sows had been vaccinated with Respiporc FLU3 in Herd 1 one month before study initiation and with Respiporc FLUpan in Herd 2 four months before study initiation. Blood and colostrum samples were collected from the sows on the day of farrowing, whereas nasal swabs and blood samples were collected twice and once weekly, respectively from the piglets. Viral load was estimated by reverse-transcriptase quantitative PCR and swIAV antibody levels in serum and colostrum were assessed by an swIAV-NP ELISA, serum neutralization and hemagglutinin inhibition -tests. Marked variation in antibody levels was observed between herds, sows, and piglets. swIAV RNA was detected in 6/20 piglets in Herd 1 and 17/20 in Herd 2. Due to the twice-weekly sampling interval, exact shedding durations could not be determined. Antibody titers at day 3 were not associated with protection against infection (p > 0.05). However, higher swIAV-NP titers prior to infection were negatively associated with shedding duration in Herd 2 (ρ = -0.67, p < 0.01). Higher swIAV-NP MDA levels were also associated with decreased serological responses after infection (ρ = -0.57, p < 0.05). Overall, MDAs showed limited protection against infection and suppressed adaptive antibody responses in a titer-dependent manner. These findings highlight substantial variability in passive immunity under field conditions and its importance for immune development in piglets.
Keywords: Colostrum; Influenza A virus; Maternally derived antibodies; Pigs; Virus neutralization test.